STOP error when pressing ctrl-alt-del to unlock a W2KPro machine

[Iain Henderson]

After installing SUS (Dec 2nd) and letting all machines apply the SUS
patches, a subset of the machines on my network are restarting with a STOP
error when pressing ctrl-alt-del to unlock the machine (not log on)

STOP 0xC0000021A (Fatal System Error) The Windows Logon Process system
process terminated unexpectedly with a status of 0x00000005 (0x00000000
0x00000000), The system has been shut down.

All affected machines are the older Small form HP e-Vectra machines, with
Windows 2000 Pro SP4 and Office 2000Pro. HP have decided it is a Microsoft
issue and therefore not their concern and have suggested re-installing the
OS. I will be reinstalling the OS on one machine tomorrow to see if it
helps.

Does anyone have any idea as to why these machines are locking up? or
suggestions for a fix

Neither of the following articles provided any resolution, but were the only
ones even close to describing our issue.

http://support.microsoft.com/default.aspx?scid=kb;en-us;330303
"STOP: c000021a (Fatal System Error)" Error Occurs

http://support.microsoft.com/default.aspx?scid=kb;en-us;823736
Your Computer Restarts Unexpectedly When You Press CTRL+ALT+DELETE to Unlock
Your Computer (Win XP)

*NB* our machines are W2KPro SP4, and do not have the language bar
indicated.

Thanks,
Iain.