My PC (running XP SP2) has recently come up with a new way to entertain itself. It reboots spontaneously at inopportune moments. So far it's done it three times. After the second time it would not start up at all. I took it to the shop where they first told me the motherboard had died, and then told me the motherboard was fine but there was dust on the RAM. So it came back and worked fine for a week, and rebooted again last night. I'm not convinced there could have built up enough "dust" since last week to be the cause. Event viewer said the following in all three cases: The computer has rebooted from a bugcheck. The bugcheck was: 0x100000d1 (0x00000000, 0x00000002, 0x00000000, 0x00000000). A dump was saved in: C:\WINDOWS\Minidump\Mini052907-01.dmp. I'm thinking it's the same driver that crashes every time, but which one? And, is it due to faulty hardware? When the PC wouldn't start up it did nothing but switch on the fan, so I really thought something physical had blown. Any suggestions and help would be greatly appreciated!