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Dreamweever66 needs to reinstall Windows. He asked the Answer Line forum where he can find that 20-digit number that tells Microsoft he bought Windows.

The fact that you have a Windows CD handy doesn't prove to Microsoft that you've paid for the right to use it. That's why you're required to enter your Product ID (PID, also sometimes called the Registration Key) when you reinstall Windows. But where do you find it?

If Windows came installed on your PC, it's probably on a sticker somewhere on your computer. If you have a desktop, check the back first. For a laptop, the bottom.

If you bought Windows separately, it should be on the sleeve protecting the disc.

If it's not in any of those places, your copy of Windows knows what it is. And the easiest way to get it is with Magical Jelly Bean's free, portable program Keyfinder (I don't make up these company names, I just report them). Just run the program and there it is.

Don't get upset if one of your security programs objects to Keyfinder. Some people consider it spyware because someone with physical access to your PC could use it to find your Registration Key. But that's really not likely, and you can remove it after using it once.

My thanks to everyone at the Answer Line Forum for contributing to my answer. You can read the discussion at

Add your comments to this article below. If you have other tech questions, email them to me at, or post them to a community of helpful folks on the PCW Answer Line forum.

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