My XP system has started rebooting frequently. It always occurs during either a mouse scroll or double click. I've disabled automatic reboot, but I still can't get a blue screen for more info. I've run the Microsoft Mem test (all 11 tests) twice - with no RAM errors. I replaced my power supply - no help. I can cause a reboot, though not always, by double clicking a shortcut that requires starting an application to load the file, such as double clicking on a .txt file or a shortcut to an Access database, etc. The system was stable for months, but both XP and Trend Micro have the automatic update feature selected. Best clue so far: I have NOT been able to trigger a reboot, nor has one occurred spontaneously, while running XP in "safe mode". Any ideas? Additional possibility - has anyone had an experience with a video card going bad and causing the symptoms above?