HP and others supply a CD-ROM with their scanners, such as the ScanJet 63XX and 74XX series, that contains the files SCSIMAP.SYS and SCSISCAN.SYS (1998 date code, rev 4.X). These files are needed on Win-98. SCSIMAP.SYS is not used in Win-2K or Win-XP.
The problem occures when the CD-Install Lizzard gratuitusly overwrites the SCSISCAN.SYS of the later operating systems, resulting in the BluScream of Death. To get the OS back up, unplug the SCSI cable.
The enclosed file (1999 date code, Rev 5.X) works for Win-2K. Just copy it over the one in C \WINNT\SYSTEM32\DRIVERS.
Simply search for all instances of SCSISCAN.SYS with pre 1999 date codes and delete them.