Software & Apps Windows How to Format the C Drive From a System Repair Disc Create a System Repair Disc to format your Windows hard drive by Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated on March 29, 2020 Command Prompt in System Recovery (Windows 7 System Repair Disc). Windows The Ultimate Laptop Buying Guide Tweet Share Email One way to format your C drive is by using the format command. If you are unable to boot Windows, you can use a System Repair Disc to format the C drive from the Command Prompt. Information in this article applies to Windows 10, Windows 8, and Windows 7. What Happens When You Format C With a System Repair Disc? The System Repair Disc does not reinstall Windows. When you format the hard drive, you remove the entire Windows operating system. This means that when you restart your computer and attempt to boot, it will not work because there's no longer anything there to load. What you'll get instead is a BOOTMGR is missing or an NTLDR is missing error message until you install a new operating system. You do not need a product key to use a System Repair Disc. How to Format C From a System Repair Disc You'll need access to a working Windows computer with an optical disc drive to create a System Repair Disc. Follow these steps to format your C drive: Insert a blank CD or DVD into your disc drive. Open the command prompt on a working Windows PC and run the command recdisc. Select your CD drive, then select Create disc. When the process is complete, insert the disk into the PC you want to format and boot from the disc drive. If you have a Windows installation DVD, you can use it instead of a System Repair Disc by following the same instructions. Select your keyboard language. Select Troubleshoot in the System Recovery Options menu. In Windows 7, choose the first option you see and select Next, then skip to step 8. Select Advanced Options. Select Command Prompt. Enter format c: /fs:NTFS in the Command Prompt to format C with the NTFS file system. If you want to format C using a different file system, you can use a different format command. Enter the volume label of the drive you're formatting (in this case, C) if promoted. The volume label is not case sensitive. If you don't know the volume label, enter Ctrl + C to cancel the formatting, then use the command prompt to find the volume label of the drive. Type Y and then press Enter when prompted to ignore the warning that all data on the drive will be lost. After the drive is finished formatting, you'll be prompted to enter a volume label, or name, for the drive. You can skip this step by pressing Enter. When you're back at the Command Prompt, remove the System Repair Disc and turn off your computer by holding down the power button. How to Format C Without a System Repair Disc There are several other ways to format the C drive if you don't have a Windows System Repair Disc. For example, if you're giving away your computer, you can wipe the drive with a data destruction program to make sure that it's impossible for anyone to recover your personal files. Alternatively, you can search for an ISO image of the Windows Repair Disc online and burn the ISO file to a USB drive. You can then boot from the USB device and follow steps 5-11 above.