Are you speaking of the games which are normally listed in All
Programs/Games? If so, go into Control Panel/Add or Remove Programs and
click on the Add/Remove Windows Components in the left pane.
With Accessories and Utilities highlighted on the first screen, click the
Details button at the bottom. On the next screen, highlight Games in the
listing and again click Details. You can add or remove any of the system
games by putting a check mark in the box next to each name or removing the
check mark. When you're done, OK your way out and the system should
reinstall the games for you.