In Episode 45 of Tekzilla Daily, Patrick Norton pointed out a website called System Requirements Lab that can help you determine if your PC has the minimum or recommended hardware and software necessary to run dozens of popular PC games.
I tried this myself and the way it works is to download either a signed Java or Active X component which collects information about your PC and compares it to System Requirements Lab's database of minimum game requirements. If you pass those requirements, it also tells you if your PC meets the recommended requirements for the game you chose. If your machine comes in above the minimum and below the recommended requirements, then certain features of the game will appear degraded or won't operate at all.
I asked System Requirements Lab if my Dell Latitude C810 can run UEFA Champions League 2006-2007. The site told me that my machine failed the CPU minimum requirement, CPU minimum speed, and video card minimum requirement test. It recommended that I buy a new machine, and referred me to a customized list at CNET.com. I guess it's a good thing that one is already on order.