Below is a simple step by step guide to remove built-in games in windows 7
1.Log on as an administrator account.
2.Click Start / Control Panel / Programs and Features
3.At the left pane , click Turn Windows Feathures on or off
4.Uncheck to box of Games ,then click ok.(See below screenshot)
5.Done.The same way ,if you want restore the built-in games,just repeat the above steps.