Driver Rollback helps ensure system stability. When you update a driver, a copy of the previous driver package is automatically saved in a special subdirectory of the system files (for every driver that you back up, a new value is added to the Backup keys located in the appropriate section of the registry).
If the new driver does not work properly, you can restore the previous driver by accessing the Driver tab for the device in the Device Manager, and clicking Roll Back Driver.
Driver Rollback permits only one level of rollback (only one prior driver version can be saved at a time); this feature is available for all device classes, except printers.
Procedure to follow
Login as Administrator and access the Device Manager for Vista users: Click Start, and then click Control Panel. Click Performance and Maintenance, and then click System. On the Hardware tab, click Device Manager.
For XP users:Click Start, and then click Control Panel.click System. On the Hardware tab, click Device Manager.
Navigate to the driver you wish to roll back, right click the name of the driver and choose Properties.
Click the Driver tab and then click on Roll Back Driver