How to Perform a Windows Vista System Restore
Click on the Start button on the bottom-left of your desktop. Click on All Programs in the Start menu. Find and click on "Accessories."
In the Accessories menu, hover your mouse over System Tools and then click System Restore. Click Yes when you get a User Account Control prompt to confirm that you want to continue.
The System Restore window will now appear, presenting you with two options:
=>> Recommended Restore
This option takes your computer back to its most recent system change. It is recommended because it restores your PC to its most recent state, that is, the state right before you installed a new program. This is especially helpful in diagnosing a problem. Selecting this option automatically launches the restoration process.
=>> Choose a Different Restore Point.
This option enables you to manually select the specific restore point that you want your PC restored to. Once you choose a restore point, click on Next to proceed. On the next screen, confirm your selected restore point and then click Next. This brings you to a second confirmation screen. Simply click Yes to proceed. This launches the restoration process.
Reboot your computer to rollback your system to your selected restore point.