Windows 7 System Restore feature will make sure that software installations, drivers, and other updates can be rolled back.If you want to disable System restore, which is a bad idea, it’s really pretty simple.
1. Click on Start-> Right Click Computer-> Properties-> System Protection
2. The System Properties dialog box opens , select your system disc and click the Configure button.
3. Under Restore Settings select Turn off system protection and click Apply.
4. You will get a confirmation warning screen. Click Yes to save.