If your still using the Windows XP or Windows 7 RC (time is running out for the RC – release candidate) you might want to be thinking about installing your Windows 7 Home Premium Upgrade that you preordered back in the summer of 2009 for $49. Didn’t catch that deal? I’m sorry.
There are several methods for upgrading. If you’re current using Windows Vista then the upgrade path is obvious. First make a backup of all of your data. While your computer is ON put in the Windows 7 disk. A setup screen will start. Just follow the prompts. Do not install the new OS over the vista install. You’ll want to start over with a clean install. After install is complete get all of the update then activate your Win7 installation. This is the easiest install. If your installing from Windows XP, Windows 7 RC or from a clean hard-drive gets more complicated. Here’s instructions from Paul Thurrott’s Supersite for Windows.