Installing Windows 7 on a relatively new machine is so simple. I can run the DVD, then once I'm done, I simply run Windows Update to find the rest of the drivers I need. Compared to Windows XP, Windows 7 is so much easier to install (as long as you're dealing with a relatively modern computer).
This holiday season, many of you will probably get a new computer. Before you throw out your old one, you may want to run a little experiment. Try installing Windows 7 and see how your old PC runs. You may be pleasantly surprised. That old machine could be used as a server, a backup PC, and much more. It's also a good idea to have an old PC running Windows XP in case you need to use an old peripheral device (although you can use XP Mode in Windows 7, it may simply be easier to use an old PC).