Helping people with computers... one answer at a time.

You can't remove a Windows operating system, but it is possible (and good practice) to reformat a hard drive and reinstall from scratch.

I have a rebuilt PC. I had Windows XP on it. An idiot put non-genuine Windows 7 on it. How do I undo this mess? I do have an installation disc for Windows XP, but no CD for Windows 7. Is it possible to uninstall or delete Windows 7 and reinstall Windows XP on my PC? Thanks for any help.

In this excerpt from Answercast #34, I look at the steps necessary to revert a computer that has been upgraded to Windows 7 back to XP.

Uninstalling windows

So absolutely. Sure, you can do that. Especially since you have the installation media for Windows XP.

  • All you need to do is to install Windows XP from scratch using that media.

It may be helpful to erase the hard disk first; and it may be safer to backup your hard disk first to make sure you don't lose anything that happens to be important to you on that Windows 7 system.

  • After backing up, erase it with a tool like DBan;

  • Then boot from the Windows XP installation disc;

  • And you should be able to install Windows XP from scratch.

  • At that point, you would simply go ahead and

    • Reinstall the applications you care about;

    • Reload your data perhaps from your backup or elsewhere;

and you should be good to go.

Article C5577 - July 12, 2012 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

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1 Comment
Mark Magill
July 17, 2012 9:37 AM

A quick PS to Leo's advice: When you do your backup, don't use a Windows-7-only backup program or you could end up "shooting yourself in the foot" when it comes time to restore. Be sure the backup program you use will run on your version of XP. The Macrium products Leo often mentions ( are a good choice.

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