You didn't mention which operating software you're running. Assuming that it's some version of Windows, you will need your Windows cd to reinstall the games.
Start/Control Panel/Add-Remove Programs/Windows Tab.
In accessories, uncheck games and proceed through the uninstall. Repeat the process except that you will need to check the box beside games, then insert you windows cd into the cd drive, and follow the on screen instructions to reinstall the games.
Hope this works for you.