Installing Microsoft Windows FAQ

Frequently asked questions about installing Windows 11, 10, 8, 7, Vista, & XP

One of the more popular sets of tutorials we've written are our walkthroughs for installing Windows. We have one for Windows 10, Windows 8, Windows 7, and Windows XP (and we're working on one for Windows 11).

Thanks to those tutorials, there's no wonder that installation and upgrading questions are some of the more common ones we get.

Below are answers to some of those questions.

What Is a Clean Install of Windows?

Basically, a clean install means to erase the drive with the existing operating system on it during the process of installing Windows. This differs from an upgrade installation ("moving" from a previous Windows version) and is basically the same thing, with a few extra steps, as a "new" install (an install on an empty drive).

Compared to an upgrade installation, a clean install is almost always a better way to install Windows. A clean install won't bring with it any problems, software bloat, or other issues that may have plagued your previous installation.

Microsoft's Windows 10 Launch In Sydney
James D. Morgan / Getty Images

You do not need a special Windows disc or any sort of other software or tools to do a clean install. All you need to do is remove the partition(s) that contain your existing operating system when you get to that step in the Windows installation process.

Here's how to do it:

All of those tutorials cover 100% of the process and include screenshots for every step of the way. Also, please know that those walkthroughs cover every commonly available edition or version available in each major version of the OS.

What is the 'Invalid Product Key' Message With a 'Code: 0xC004F061' Error Mean?

Here's the full error message, all inside an Invalid product key window:

The following failure occurred while trying to use the product key:

Code: 0xC004F061 Description: The Software Licensing Service determined that this specified product key can only be used for upgrading, not for clean installations.

The 0xC004F061 error appears during the Windows activation process if a) you used a Windows upgrade product key but you b) did not have a copy of Windows on the drive when you clean installed.

The message at the bottom of the window indicates that you can't use this product key for clean installations but that isn't entirely true. A Windows clean install is fine, but you must have had an upgrade-valid version of Windows on the computer prior to the clean install.

The Microsoft-supported solution to this problem is to reinstall the previous version of Windows and then clean install Windows. However, another solution is to do an in-place upgrade of Windows to the same version of Windows. Yes, it seems strange, but according to several sources, you'll be able to successfully activate Windows after that process completes.

If neither of those solutions work, you'll need to purchase a Windows System Builder disc (sometimes referred to as an OEM disc) which you will be able to install on an empty hard drive or clean install over a non-upgrade-valid version of Windows (e.g. Windows 98, etc.) or a non-Windows operating system.

It's important to realize that during the Windows clean install process, when you enter your product key, you are not warned about the possibility that you're using the wrong key. That stage in the Windows installation process just checks to see if the product key is valid at all, not if it's valid for your specific situation. That determination occurs during the activation process after Windows is completely installed.

How do I Move Windows Installation Files From a DVD to a Flash Drive?

This process isn't quite as easy as it might sound, so some dedicated tutorials are required:

Unfortunately, just copying the files from your Windows installation disc to an empty flash drive won't do.

How do I Get an ISO File on a DVD or Flash Drive so I Can Install Windows?

That ISO file you have is a perfect image of a Windows installation disc, contained in a neat one-file package. However, you can't just copy that file to a disc or a flash drive and expect to use that to install Windows.

If you want to install Windows from a DVD, see How to Burn an ISO File to a DVD for instructions.

If you want to install Windows from a flash drive, you can follow one of the same tutorials we linked to in the last question.

Can I Install My Copy of Windows on a New PC as Long as I Remove It From My Previous Computer?

Yes. The biggest point being: you must remove Windows from the old computer before you activate it on the new one. In other words, you can only have your copy of Windows running on one computer at a time.

Another thing to keep in mind is that if you installed an upgrade licensed copy of Windows on a computer and then want to use it on another computer, the same "upgrade rules" apply: you'll need to have a previous version of Windows on the computer before installing the upgrade.

You can not "move" Windows to another computer if it came preinstalled on your computer. Your copy of Windows is OEM licensed, which means that you are only allowed to use it on the computer that it came already installed on.

Are There Limits on Reinstalling Windows on Different Computers?

There are no limits to the number of computers that you reinstall Windows onto so long as you follow the rules discussed in the last question.

Do I Have to Buy Another Copy of Windows If I Want to Install It on Another Computer?

The answer to this is probably clear if you've read the last few answers, but: Yes, you will need to buy a license to install Windows on each and every computer or device you plan on using it on.

Why Didn't the Windows Setup Program Begin Even Though My Windows DVD (or Flash Drive) is in the Computer?

Chances are good that the boot order in BIOS or UEFI is not properly configured to look at your optical drive or USB ports for bootable media before it checks for the same from the hard drive.

See How to Change the Boot Order in BIOS or UEFI for help.

What do I do if my Computer Freezes (or Restarts or Gets a BSOD) During the Windows Installation Process?

Try installing Windows again. Sometimes problems during a Windows installation are temporary, so another shot is a good first step. If you're doing a clean install, just start the process over again. Since part of a clean install involves formatting the drive, whatever issues might exist with this partial installation will be gone.

If just starting the Windows install over again doesn't work, try removing/unplugging any unnecessary hardware from your computer before starting the installation process. The Windows setup process could stall or produce an error if it's having an issue installing some piece of hardware. It's much easier to troubleshoot an installation problem with a piece of hardware once Windows is up and running.

Finally, be sure that your computer's BIOS or UEFI is updated. These updates by your computer or motherboard manufacturer often correct compatibility issues with operating systems like Windows.

How Does Windows Already Know My Phone Number?

Near the end of some Windows setup processes, if you choose to use a Microsoft Account to sign in to Windows, you'll be asked to provide or verify your phone number.

If your phone number is already listed, it just means that you've previously provided it to Microsoft when you created your Microsoft Account. You probably have a Microsoft Account if you've ever logged in to another Microsoft service in the past.

Is There a Price Difference Between a Download and a Boxed Copy of Windows?

The majority of what you're paying for is the license to use Windows, so downloading it isn't advantageous from a cost standpoint as much as it is from an ease-of-use or quick turnaround perspective.

Are the Major Windows 11 Updates Free?

Yes. All Windows 11 updates are free. Learn how to check for and install Windows updates.

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