Hi tech gurus, My first post, so apologies if my etiquette isn't perfect! I have an XP Pro SP2 system with an Athlon 3400 and 512mb PC3200 RAM and a Radeon 9500, with an 80Gb Samsung Spinpoint HDD in an Ideq 210P SFF chassis. Since January I have been experiencing apparently random crashes when I run any apps which seem to use a reasonable amount of RAM or do any CPU work. I have reinstalled the OS & SP, swapped the HDD for an older one and reinstalled XP Pro, SP2 and drivers, virus scanned, rootkit scanned, spyware scanned and run a number of registry fix programs. Nothing worked. I took my system to my local PC system builder who actually seems to understand all these configuration issues (not the frequently encountered small time system builder and professional shrugger when presented with something tricky). He ran some diagnostics, swapped the CPU and RAM and tried them in other systems, and found no problem. This only left the MB and chassis which he couldn't test, so I returned the system under warranty and had it repaired. I don't know what was supposed to have been fixed, but it looks like a new MB to me. Same problem has occurred though. I've run Memtest and found no fault. Sometimes the system freezes, sometimes it just reboots. When I get a reboot, there is a System error entry (category 102, event 1003) in the event log which seems to be the culprit which says something to the effect of:- Error code 10000050, parameter1 b786eb1c, parameter2 00000001, parameter3 bf87b6c6, parameter4 00000000. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. This seems to be a kernel error. Each time the system restarts, I get a dialog box with this message:- Microsoft Windows The system has recovered from a serious error. A log of this error has been... I've tried the link and it doesn't seem to have a KB entry to cover my situation. I'm completely out of ideas now, I think there may be some sort of driver conflict, but don't know where to start. I have a minidump error which I can post if there is anyone out there who thinks they may be able to work out what is going on. Any help would be greatly appreciated!