As you may know, you cannot make a clean install of Windows 7 upgrade on a formatted disc. You can only install this OS on a hard disc that has a previous version installed (XP, Vista, whatever). So, if you bought a Windows 7 UPGRADE (not the full version), you will have no luck just popping the disc into the DVD drive on a computer with a disc wiped clean. I bought the Windows 7 upgrade thinking I could do this. I was going to install it on a Gateway computer with Vista 64 originally installed. However, I want to install a new motherboard in this computer, which means that the Recovery Disc for the original Gateway computer will not recognize this new MB if I run the recovery program for the old MB (and halt the Recovery installation). With this system of installation, you're going to have to have two previous versions of Windows. Luckily, I have the original Windows XP/SP-2 and Windows 98 discs with the installation numbers. So, here's how I solved my particular problem of installing the Windows 7 upgrade on what amounts to a custom-made computer (As far as I'm concerned, this installation can't be illegal because I own the XP and 98 discs used previously on other computers). Put the XP disc into the DVD drive. Go through the installation procedure (don't worry if you don't have chipset and RAID discs during this process--unless you want to install them). When the XP installation asks you to provide a disc from a previous version of Windows, put in the Win 98 (or Win 95 disc) Finish the installation process. When you boot up to XP, you'll most likely be in primitive mode screen 'cause you don't have a bunch of drivers needed for your computer. This doesn't matter because the next thing you'll do is put in the Windows 7 UPGRADE install disc (which will format your disc again throught the Custom Install setting), getting rid of XP--thus a virgin install). Of course, if you have a factory computer with Vista installed, just put in the Windows 7 disc, have the hard drive formatted during the installation process and then install the OS. You're going to have to get drivers not installed during the Windows 7 process--but you will boot into Windows 7. If you have a custom-made computer that you assembled yourself, you'll most likely know what to do from this point forward.