Here at the data center we can take no chances of down time. We refresh all hard drives a regular schedule. The new hard drives are put through a rigorous test for 5 days before being deployed. We backup the OS only when maintenance or new programs installed. The user data resides on 3 hard drives. The user data is backed up with user written executives. A second computer is standing by in case of out and out failure of TI to restore drive C. The motherboards of the two computers are different but we have learned how to restore to different motherboards and make the OS work. The OS is WIN98/SE. This OS has proven to be the most dependable and stable OS at the data center. TI has saved many a day for us. Our computers run 24/365.