 So the topic of today's video is how to downgrade a copy of Microsoft's Windows 7 Professional or Windows 7 Ultimate. So what downgrade means is that for the first 18 months after October 22, 2009, you are allowed to buy a copy of Windows 7 Professional. Then what you do is you call up Microsoft Customer Service at 1-800-936-5700. Basically what you say to them is, okay, I bought a copy of Windows 7 and I want to use Windows XP for now. So what you're able to do is you give them your Windows 7 product key, which is on the back here, and I'm not going to show you that too carefully. They read you out, well first of all they verify your Windows 7 product key, then they read you back a Windows XP product key. Then you just take any old Windows XP disk that you can find, you can even download an ISO if you have a TechNet subscription, and then you install Windows XP using that key. When you're finally ready to go to Windows 7, maybe your office is upgrading all at the same time, or maybe you're just not quite ready, but you just want to buy Windows 7 so you have it for later, all you do is pop in your Windows 7 CD and install Windows 7. And that will invalidate the Windows XP license that you are using temporarily. Thanks for checking out my video blog on Windows 7 downgrade.