STOP: error after upgrading to SP4

I have a P3 800 on a DFI CA61b motherboard with 512mb sdram, 2 20gig wd ide drives, an Adaptec 1520b/1522b ISA adapter with an stt80000 tape drive.I am running Windows 2000 Server w/10 clients. Software supplier requested an update to SP4. I run sp4 and reboot and get a STOP: 0x0000007B error. I removed the SCSI controller and the cdrom and checked for virus. Don’t know what else to check.