When data requested from memory is not found, a memory fault is created. Windows then looks for the same data in the virtual memory on your hard drive. If the data is not there either, a stop message appears alerting you of the event. While this problem is usually the result of damaged memory or other hardware malfunction, it is occasionally caused by a corrupted file system. If you suspect or have confirmed that the problem is related to your file system, reformat the computer to correct the problem. Prior to reformatting, run the Check Disk utility while in Windows Safe Mode and back up your