My son and I are trying to set up a computer for college. Celeron 400 ppga on a ABIT BM6. We had some initial problems with setup "CMOS Checksum error" and lockup and now a week later it has crashed a couple times and last evening refused to reboot Win98. Took the case off today was able to reset the bios to defaults and got it working fine. Had thought the problem was perhaps a short, but now wonder if it is heat related. This is a Intel retail heat sink and fan. Running at 400 with no overclocking. What rpm should we get from the retail fan? What temp reading from the board is considered too high? Monitor with the ABIT included program? Thanks.