Windows terminates unexpectantly during startup

Whenever I attempt to start Windows Xp (ser.pks 1&2) it shuts down. It has a
blue screen with the following message at the top:

windows logon process terminated unexpectantly with a status of
0XC0000005
(0X00000000 0X00000000).
The system has shutdown

I have tried using F8 and choosing rollback and safe features - no good.
I have even used the Recovery Console and exercised CHKDSK /R which checks
the hard drive and all system files. Still no start.

I have used Norton Anti-virus (via Norton's recovery disk) and scanned my
entire harddrive with the latest (8/28/06) virus definitions - no virus was
found.
Getting kind of desperate. Anyone out there ever had or heard of this
problem??
Help!