I've just performed a Windows Update loading Service Pack
6a on a HP Vectra loaded with NT 4.0 Workstation.  
Unfortunately I can no longer log into this machine as I
get a Dr. Watson error (machine boots fine - I just can't
login) and then a Fatal Error resulting in Blue Scren
C000021a.  I believe this is covered in Knowledge Base
article 311860.  Any ideas on how I can recover from this?
Thanks!