Hi, Am getting random restarts and system errors, as follows: Error code 000000000000009c, parameter1 0000000000000000, parameter2 fffffadf90881240, parameter3 00000000b2000040, parameter4 0000000000000800. Initially thought it was overheating (am not overclocking) but it happened again today with CPU (Q9300) temps at ~45. Tried to donwload dumpchk but it seems to be obsolete now (according to MS support). Running Xp x64, SP2, has been stable since building 12 months ago, then suddenyl getting errors. Ran memory checker for 4 hours with no errors. Have included four minidumps here - if anyone can work out what's going on I'd be hugely grateful. TIA I just noticed in event viewer that (usually) just before the 1003 error there's three of the following errors: Event ID 122 Source WMIxWDM Machine Check Event reported is a fatal Bus or Interconnect error. Memory Hierarchy Level: 3 Participation: 3 Request Type: 0 Memory/IO: 3 Address: 0 Don't know if this is significant or not.