Microsoft has pulled an AMD SCSI driver from Windows Update after it was found to cause boot problems for numerous people. Reports came from many users who experienced boot problems, BSoDs, ...
If you're wondering, those empty primary IDE channels were occupied by a spare hard drive (moved to file server) and a CD-ROM drive (broke). The only change I made was upgrading the FastTrak66 driver.
I'm working on an NT 4.0 machine (SP 5) and it intermittently gets the "0x0000007B Inaccessible Boot Device" BSOD. I looked it up on Microsoft ( LINK) and it seems to point to a bad registry/driver or ...