How to Clean Install Windows 8 or 8.1

Do a Windows 8 install from scratch

What to Know

  • Back up important data > locate the product key > disconnect unnecessary hardware > start clean install.
  • Insert Windows installation media > turn on/restart computer > press key to boot when prompted.
  • Follow prompts > enter product key > select Custom: Install Windows only (advanced).

This article explains how to perform a clean install (a.k.a "custom install") of Windows 8 and Windows 8.1 on your computer. It's nearly identical for both versions, but we've called out the differences where appropriate.

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Plan Your Windows 8 Clean Install

Windows 8 laptop computer

Karlis Dambrans / Flickr / CC BY 2.0

The most important thing to consider before starting is that every bit of information on the drive you're going to install/reinstall Windows 8 on will be erased.

This means the entire operating system that's on there now, whatever that may be, will be gone, as will all the programs you've installed, and, most importantly, all your precious data you've saved to that drive.

Back Up Your Important Data

The first thing to do, if you can, is back up whatever data you'd like to keep, like your saved documents, downloaded music and videos, etc. Backing up your actual programs isn't usually possible, so locate all the installation media and downloaded installation files you used to install the programs so they're available to reinstall once the clean installation is done.

Be sure also to back up any data files from your programs, assuming they have any, that might not be located with your other saved files.

If you were proactive and have been using an online backup service or local backup tool, then once Windows has been reinstalled, you can restore your data from the backup location.

Locate Your Product Key

Your next concern should be your product key. This 25-digit alphanumeric code is required during the clean installation process.

If you've purchased Windows 8 yourself, the product key should be included with the DVD media you received or in the email confirmation you received when you purchased it for download.

If Windows came preinstalled on your computer, look for a sticker with the product key somewhere on your desktop, laptop, or tablet device.

If you can't locate the key but the following is true: a) Windows is installed on the computer right now, b) it's working, and c) it was not preinstalled by your computer maker, then you do have the option of extracting the key from your current installation. There are programs called "Windows product key finders" that can do this.

Disconnect Unnecessary Hardware

Windows should install fine with all of your hardware connected, internal and external, but if you run into trouble, or have had trouble installing Windows on this computer before, removing unnecessary internal components (if you have a desktop) and disconnecting USB and other external devices should help.

Once the installation is complete, you can connect those devices one at a time.

Start the Windows 8/8.1 Clean Install

Once you are absolutely positive that everything on the primary hard drive partition you're about to install Windows on, probably your C: drive, can be removed (i.e., you've backed everything up that you want to keep), then proceed on to the next step in this tutorial.

Please remember that once you delete everything from this drive, which is done in a later step (we'll let you know when), you won't be able to get any of that data back.

The procedure described, and screenshots shown, in these steps refer specifically to Windows 8 Pro but are equally valid for the standard Windows 8 edition that's also available, as well as both editions of Windows 8.1 as we mentioned earlier.

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Boot From the Windows 8 Installation Media

Press any key to boot from CD or DVD screen

To start the setup process, you'll need to boot your computer from whatever installation source you happen to be using: either a disc or a flash drive.

In other words, if you have a Windows 8 DVD and you would like to install Windows from an optical drive, then boot from the disc. Alternatively, if you have the installation files properly copied to a USB based drive, then boot from the USB device.

See the What to Do... section further down this page if you need to change the media (disc vs flash drive) that you install Windows from, or if you have an ISO file of the OS and you're not sure what to do with it.

There are really three basic steps here:

  1. Insert the disc into your optical drive, or plug into a free USB port the flash drive with the Windows installation files on it, and then turn on or restart the computer.
  2. Watch for a Press any key to boot from CD or DVD message (shown above) if you're booting from a disc, or a Press any key to boot from external device message if you're booting from a flash drive or other USB device.
  3. Press a key to force your computer to boot from either source.

If you don't press a key during this step, your computer will try to boot from the next device listed in the boot order in BIOS, probably your hard drive, in which case your currently installed operating system will start. If that happens, just restart your computer and try again.

If you don't see one of the messages above, and your current operating system starts or you receive some kind of error, the most likely reason is that the boot order is set incorrectly. You probably just need to change the boot order in BIOS, being sure to rank the CD/DVD Drive or External Devices entry somewhere before or above the hard drive in the list.

It's also OK if you don't see one of the above messages, but the setup process (see the next step) does being automatically. If that happens, just consider this step over and move on.

What to Do If Your Windows 8 Installation Media Doesn't Work for You

Considering the facts that Windows 8 can be purchased online and downloaded in ISO file format and that many computers, especially tablets and other smaller computers, don't have optical drives, it's possible you could find yourself with the setup files in some format, or on some media, that simply isn't going to work for your computer.

Below are some solutions based on common situations that people find themselves in:

Problem: You have a Windows 8 DVD, but need to be able to install Windows from a USB device. This is probably the most common problem we hear about.

Solution: Locate a flash drive that's at least 4 GB in size and that you can remove all the data from. Then see How to Install Windows 8 From USB for help creating a disc image of the DVD, and then getting that image properly copied onto a USB flash drive.

Problem: You downloaded a Windows 8 ISO File and need to install Windows from a DVD.

Solution: Burn the ISO file to a DVD (or BD) disc. This is not the same as simply burning the ISO file itself to a disc, like you would with a music or video file. See How to Burn an ISO Image to a CD/DVD/BD for help.

Problem: You downloaded a Windows 8 ISO File and need to install Windows from a USB device.

Solution: Find a flash drive of at least 4 GB total capacity that you can erase everything on. Then go to How to Install Windows 8 From USB for help getting that ISO file onto a flash drive properly.

Once you have the files on the installation media that you want, come back here and follow the directions as given above to boot from the disc or flash drive. Then you can continue on with the rest of this process.

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Wait for the Windows 8 Installation Files to Load

Windows 8 Setup Loading Screen

You'll know the Windows setup procedure is starting properly if you see the splash screen as shown above.

During this time, Windows 8 Setup is preparing by loading files into memory so the setup process can continue. Don't worry, nothing is being erased or copied to your hard drive right now. That all happens a bit later on.

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Choose Language, Time, and Other Preferences

Windows 8 Setup Language and Other Preferences Screen

Choose the language to install, the time and currency format, and the keyboard or input method you'd prefer to use in Windows and throughout the installation.

Once your options are selected, select Next.

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Select Install Now

Windows 8 setup screen

Choose Install now in the middle of the screen, right under the Windows logo.

This will get the installation process underway.

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Wait for Windows 8 Setup to Begin

Windows 8 Setup is Starting Notification

The setup process is now beginning.

Nothing to do here but wait. You might see this screen for several seconds, but not for too much longer than that.

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Enter Your Windows 8 Product Key

Product Key Entry Screen during the Windows 8 setup

Here's where you enter your product key, the 25-digit code you received when you purchased the operating system. You don't need to enter the dashes that are probably shown as part of your product key.

It's completely legal to reinstall Windows 8 via this clean install method. So long as the product key you use to install it is only used on one computer at a time, you're not breaking any rules.

If you downloaded Windows, chances are the product key is in your purchase confirmation email. If you purchased a DVD in a retail store or online, your product key should have been included alongside your disc.

If Windows 8 came preinstalled on your computer, and you're now performing a clean install on that same computer, your product key is probably located on a sticker somewhere on your computer or device.

Once you've entered the product key, select Next.

Entering your product key at this point is required. This is unlike in previous versions of Windows, where you could skip the product key entry during installation as long as you provided one within a certain time frame, usually 30 or 60 days. Also unlike in previous versions, activating your product key online is automatic and part of this process.

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Accept the Windows 8 Software License Agreement

Windows 8 License Terms Acceptance Screen during setup

The next screen you encounter will be the Microsoft Software License Agreement page, which is essentially a giant text box containing the license terms for the edition of Windows you're installing.

Read through the agreement, check the I accept the license terms box, and select Next.

You should always read software license agreements and look for caveats you might not have expected, especially when it comes to operating systems. Microsoft, as well as most other software makers, have strict and legally binding limits as to how many concurrent computers their software can be operated on. For example, a copy of Windows 8 can only be installed on a single computer at a time. In reality, this means one product key per computer...period.

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Choose the Custom Installation Method

Windows 8 Installation Type Screen during setup

The next screen presents you with an important question: Which type of installation do you want?.

Select Custom: Install Windows only (advanced).

Even if you're upgrading from a previous version of Windows, we don't recommend that you upgrade. It sounds like a great option, with your files, settings, and programs all remaining in place, but the reality is often much different. You'll get better performance from Windows 8 and whatever software you choose to install again if you continue with this clean install procedure instead.

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Show the Windows 8 Advanced Drive Options

Windows 8 Setup Partition Management Screen

On the Where do you want to install Windows? screen, you'll see a list of all the partitions that Windows sees on the computer.

The thing that makes a clean install "clean" is the removal of the partition that the current operating system is installed on, as well as any auxiliary partitions that the operating system was using, usually for recovery purposes. This is what we're going to do over the next several steps.

If, and only if, you're installing Windows on a new or previously formatted hard drive, which of course has nothing that needs to be removed, you can skip directly to Step 15!

Windows 8 Setup considers partition management an advanced task, so before we can remove any partitions, you'll have to choose Drive options (advanced).

Over the next few steps, you'll remove the partition(s) for the operating system that you're replacing with Windows 8. Remember, it doesn't matter what operating system is currently on the computer—an old installation of Windows 8, a newer Windows 11 one, Ubuntu Linux, Windows 7, etc.

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Delete the Partition You Plan on Installing Windows 8 Onto

Windows 8 Setup Advanced Partition Management Screen

Now that you have access to the full range of partition management options, you can delete any partitions from your hard drive that are used by the currently installed operating system.

Before you delete a partition, please know that all data on that partition will be erased forever, meaning the operating system itself, all installed programs, all saved documents, movies, music, etc. that might be on that drive. It's assumed that, by this point, anything you wanted to keep you've backed up elsewhere.

Highlight the partition you want to delete and then select Delete.

Your list of partitions may differ considerably from ours, which you can see in the screenshot above. There's one 60 GB physical hard drive on our test computer that we previously had Windows 8 installed on. The primary partition, which is the C: drive when logged into Windows, is 59.7 GB. That other small partition (350 MB) is a supporting partition that we also plan on deleting, which we'll get to in a few steps.

If you have multiple hard drives and/or multiple partitions on any of your drives, make sure you're deleting the correct partition(s). Many people have second hard drives or partitions that they use for backup. That's not a drive you want to be deleting.

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Confirm the Partition Deletion

Windows 8 Setup Partition Removal Confirmation Dialog

After choosing to delete the partition, you'll be prompted to confirm that you really do want to delete the partition.

As we spelled out in the last step, please be aware that all the data stored on this partition that you're removing will be lost forever. If you haven't backed up everything you want to keep, select Cancel, end the install process, restart your computer to boot back into whatever operating system you have installed, and back up anything you want to keep.

To be completely clear: This is the point of no return! We don't mean to scare you, especially since this is a necessary step to take during a clean install. We just want you to have full knowledge of what you're about to do. If you know there's nothing on your primary drive you still need to back up, then you should feel completely comfortable continuing.

Select OK to delete the selected partition.

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Delete Other Partitions Used by the Previous Operating System

Windows 8 Setup Advanced Partition Management Screen

If there are other partitions you need to delete, like recovery partitions in use by the previously installed operating system, now is a good time to remove them. You probably only have one of these auxiliary partitions, and probably only if you had a previous version of Windows installed.

For example, in Windows 11, 10, 8, 7, and some Windows Vista installations, a small recovery partition, labeled here as System Reserved, is created and populated automatically during that operating system's installation. The same thing will happen behind the scenes as you continue to install Windows 8. However, you no longer need the one installed by the previous Windows installation, so you can remove it.

To do so, repeat the same process you followed to remove the primary partition in the last few steps: highlight the partition you want to delete and then choose Delete.

You might notice that the first partition we deleted appears to still exist. Look closer, however, and you can tell that it's gone. The description now says Unallocated Space and there's no longer a partition Type listed. In other words, this is now empty space, which we're getting close to putting Windows 8 on.

Again, make sure you're not removing partitions you don't really want to remove. One of these Windows auxiliary partitions will clearly be marked as System Reserved and will be very small, probably 100 MB or 350 MB depending on the version of Windows that you had installed.

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Confirm Other Partition Deletions

Windows 8 Setup Partition Removal Confirmation Dialog

Just like you did a few steps back, Windows Setup will prompt you to confirm the removal of this other partition.

Select OK to confirm.

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Choose a Physical Location to Install Windows 8

Where To Install Windows 8 Screen during setup

As you can now see, all the space on this hard drive is listed as Unallocated Space. In other words, it has no partitions set up and the soon-to-begin installation or reinstallation of Windows 8 will be "clean" and "from scratch" on this empty drive.

The number of partitions displayed and whether those partitions are unallocated portions of a hard drive, previously partitioned spaces, or previously formatted and blank partitions will depend on your specific setup and what partitions you've deleted in the last several steps.

If you're installing Windows on a computer with just one physical hard drive on which you've just removed all the partitions from, your Where do you want to install Windows? screen should look like the one pictured above, aside from the fact that your drive is probably much bigger than our 60 GB example one.

Select the appropriate unallocated space to install Windows 8 onto and then choose Next.

You don't need to manually create a new partition, nor format one, as part of the setup process. These two actions are completed automatically, in the background, between this step and the next.

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Wait While Windows 8 Is Installed

Windows 8 setup copying and expanding installation files

Windows Setup will now begin installing Windows 8 onto the partition it created from the free space you selected in the last step. All you have to do here is wait.

This step is the most time-consuming of them all. Depending on your computer specifications, this process could take anywhere from 10 to 20 minutes, possibly more on slower computers.

This is completely automatic, and the next step involves a reboot of your computer, which you do not give explicit permission to do. So if you step away, and things look different from above, just continue through the next steps until you catch up.

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Restart Your Computer

Windows 8 setup about to restart the computer

As the bulk of the installation process ends, your computer will reboot automatically.

If you happen to catch this screen, which is only there for ten seconds, you can select Restart now to manually force the restart.

Your computer will likely present you with that Press any key to boot from option as it starts up again and sees the boot information from your Windows 8 installation media again. Don't press a key, or you'll end up booting to the installation disc or flash drive again, which you don't want to do. If you accidentally do that, just restart your computer and don't press anything at that time. The Windows installation should continue again as shown on the next screen.

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Wait for Windows 8 Setup to Begin Again

Windows 8 Splash Screen

Now that your computer has restarted, Windows 8 can continue installing.

There's nothing to do here. Windows Setup has a few important things it still needs to do before it's done, but none of them require user intervention.

You might sit at this screen for several minutes before you see Getting devices ready, which we talk about in the next step.

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Wait for Windows 8 Setup to Install Hardware

Windows 8 Getting Devices Ready Screen

As you're waiting for the Windows 8 clean install to finish up, you'll notice an indicator that works its way up to 100% in several fits and starts.

In the background, Windows is identifying all the hardware that makes up your computer and installing the appropriate drivers for those devices, if available.

This process usually takes just a few minutes, and you may see your screen flicker and go blank from time to time.

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Wait for Windows 8 to Finish Installing

Windows 8 Getting Ready Screen

After Windows Setup finishes installing hardware, you'll see a Getting ready message at the bottom of the screen.

During this short stage, Windows Setup is finishing up the last few tasks, like finalizing the registry and other settings.

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Wait While Your Computer Restarts Automatically

Restarting Your PC Screen after a Windows 8 install

This screen only shows up for a second, maybe less, so you may not even see it, but as you can see in the screenshot above, Windows setup says Restarting your PC and then promptly does just that. This is the second, and final, restart required during the installation.

Just as you were warned about several steps back, you'll probably get that Press any key to boot from option again as your computer turns back on, but don't do it. You don't want to start the installation process over again, you want to boot from your hard drive, which now has an almost-complete installation of Windows 8 on it.

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Wait While Windows 8 Starts Up

Windows 8 Splash Screen

Once again, you're waiting on Windows to start up. This should only take a minute or two.

You're almost done waiting through boring black screens, we promise!

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Wait for the Windows 8 Basics Wizard to Start

Windows 8 Installation Basics Wizard Home Screen

The next screen you see is an introduction to a wizard you're about to complete that helps customize Windows to your preferences.

Four sections are shown, including PersonalizeWirelessSettings, and Sign in.

This screen only appears for a few seconds before moving on to the screen detailed below.

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Pick a Color Theme & Name Your PC

Windows 8 Setup Personalize Screen

Two pretty simple options are presented now: one for the color you like and another for the PC name.

The color you choose helps shape the display on your future Windows 8 Start Screen, and in some other areas of Windows. This is easily changed later from the Start screen area of PC settings, so don't get too caught up on this one.

The PC name is just a friendly phrase for hostname, the name that identifies this computer on your network. Something identifiable is always good, like timswin8tablet or get the idea. You can always change this later.

Select Next when complete.

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Join a Wireless Network

Windows 8 Setup Image Placeholder (No Image)

On this screen (not shown, we're working on getting a good screenshot of this step), choose from the list of available wireless networks that Windows sees at the moment.

Once decided, enter the password if the network is encrypted and requires one.

Select Next to continue.

You won't see this step if your computer doesn't have wireless network capabilities or if Windows 8 doesn't have an included driver for the wireless hardware and so wasn't able to enable that device. Don't worry if the latter is the case—you can install the correct wireless driver after the clean install is complete.

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Use Default Settings or Set Custom Ones

Windows 8 Setup Settings Screen

On the Settings screen, you have the option of accepting Microsoft's recommended default settings for Windows 8, which are detailed on-screen, or customizing them to your preferences.

For the most part, there's no problem accepting the express settings.

Choose Use express settings to continue.

If you'd like to explore your options, you can select Customize and walk through a series of additional screens with settings for network sharing, Windows Update, automatic feedback to Microsoft, and more.

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Sign in to Your PC With a Microsoft Account...or Don't

Windows 8 Setup Sign in to your PC Screen

The next screen is the Sign in to your PC step.

You have two pretty big options here for how to sign in with Windows 8:

Sign in With Your Microsoft Account

If you already have an email associated with a major Microsoft service, then you can use that here. If you don't, that's OK; enter any email address and Microsoft will create an account for you based on that email address.

The advantage of using a Microsoft account is that you can easily use the built-in app store, you can sync major settings between multiple Windows computers, and more.

Sign in With a Local Account

This is the standard way that previous versions of Windows, like Windows 7, Windows Vista, and Windows XP worked.

Your account is only stored locally on this Windows 8 computer. Please note though that you'll still need to create a Microsoft account, or use your current one, some time in the future if you plan on using the store to download apps.

Our recommendation is to use your existing Microsoft account or create a new one.

Assuming you decide to do that, enter your email address and then choose Next.

The next several screens (not shown) will verify your account, ask for your password, and may ask for a telephone number or other information to help with password recovery. If you're setting up a Microsoft account for the first time, you may see some other screens as well. If you're signing in with an existing account, you may be asked to confirm a code sent to your email or phone, copy settings and apps from other Windows 8 computers, etc.

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Wait While Windows 8 Creates the Local Portion of Your User Account

Windows 8 Setup Creating Your Account Screen

Even though you may have chosen to create, or use your current, Microsoft account, there is still a local account created to help facilitate that.

This is what Windows 8 is doing while the Creating your account or Setting up your account message is on screen.

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Wait While Windows 8 Finalizes Settings

Windows 8 finalizing your settings

Remember all of those personalization and other settings you just made? Windows 8 is now committing those to your user account it just created.

Just wait during this short phase.

The clean install is almost done...just a few more steps.

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Wait While Windows 8 Prepares the Start Screen

Windows 8 We're Getting Your PC Ready Screen

Depending on the version of Windows 8 you're installing, you may sit through a long series of screens, the first several of which explain how to work with the Windows 8 interface.

That, or maybe you'll see some large messages in the middle of the screen. The background will continually change colors as this progresses, and you'll see Installing apps at the bottom of the screen.

Regardless, this whole series of screen changes and messages should only take a few minutes, at most.

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Your Windows 8 Clean Install Is Complete!

Windows 8.1 Start Screen

This completes the final step of your clean install of Windows 8! Congratulations!

What's Next?

Most importantly, if you chose not to enable automatic updates (Step 26) then the first step after installing Windows is to head to Windows Update and install all the important service packs and patches that have been issued since the version of Windows 8 you just installed was released.

If you did enable automatic updates, Windows will prompt you about any important updates needed.

After Windows updates, you should update any drivers that Windows didn't automatically install for your hardware during installation. You might also want to update drivers for any devices that don't seem to be working correctly. See How to Update Drivers in Windows 8 for a complete tutorial.

You might also want to see our Windows 8 Drivers page, which contains information and links to drivers from some of the more popular computer and device manufacturers in the world. This is an especially helpful resource if this is your first Windows 8 clean install and you're locating Windows 8 drivers for the various parts of your computer for the first time.

We also highly recommend that you create a Windows 8 Recovery Drive, a flash drive that you can use to troubleshoot problems in the future, even ones where Windows won't start at all.

Finally, if the installation media you installed Windows with didn't include the Windows 8.1 update (it will say on the disc or in the ISO file name), then you should update to Windows 8.1 next.

What Is a Clean Install?

A Windows 8 clean installation involves removing the existing operating system installed on a partition (a previous Windows 8 installation, Windows XP, Windows 10Linux, Windows 7... it doesn't matter) and then installing Windows from scratch on that same drive.

If you're considering uninstalling Windows 10, it's not that hard to do.

In other words, a clean install is the erase-whatever-is-there-and-install-a-new-copy-of-Windows-8 process, and is usually the best method of installing or reinstalling Windows. We always suggest a clean install over upgrading, say from a previous version of Windows like Windows 7. Look through our Windows Installation FAQ if you're having concerns about this.

The Windows 8 end of life was in 2023. To ensure your computer will continue to receive important security updates, consider upgrading to a modern OS like Windows 11.

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