I am servicing a customer PC with xp Pro with a d85gbf intel board with 1 gb of memory and onboard video. The complaint was of the computer rebooting itself 2-3 times a day. I ran the gambit of stuff. Virus/spyware scan, CCleaner etc. My memory test came up with a failure in the 4th memory stick where one of the lines would write an 8 when it was supposed to write a 0. This happened on the inverse coupling test and mats+ I switched the sticks around to see if that had any effect which it didnt. I fiddled with the memory for a bit until I found that any stick in the 4th dim would cause failures in the memtest. I removed one stick and kept the 4th slot free and told the customer to test it out for a couple of days. He did so and when I called him back, he said the computer had not rebooted, but the video resolution was dropping and he was having to restart to get the video back. So I went back down with a spare pci video card. I installed updated video drivers for the onboard video and installed the pci video card and instructed the customer to move his monitor cable to the video card plug if he had the video problems again. I said I would call back at the end of the week. I called the customer back and he had said the computer was running perfectly. So I headed back down onsite and uninstalled my video card and headed back to the shop. On the way back the customer called me and said the computer rebooted itself. The error message said LSA Shell had recovered from a serious error and needed to close! I still think the motherboard needs to be replaced, but I wanted to run it by you guys to see if you had this problem first. This has been a heck of a day! Other notes: This would be the first time an error report has been generated for the reboot problem. Before hand, the only error/warning was the userenv hang error which I installed the hive cleaner tool from microsoft. Otherwise, the error log is completely clean.