So Extreme112, Like I said, It depends on the game. Most should run in compatibility mode but there are some that won't. And if you really really want to play the game, then you have the option Lexluethar mentioned, which is to install the game on a virtual machine running the OS needed (in the case of your question, Windows 2000).
We might be able to give you more help if you mention the game or games you want to play.