C0000021a error during startup of WinXP compaq laptop

[Richard]

I have compan laptop with winxp installed.
Today I decided to download and install SP1, after the
installation finished about 90% my computer froze, so I
did a cold boot and now I am getting the following error
message.

STOP 0xC000021A {Fatal System Error} The Windows Logon
Process system process terminated unexpectedly with a
status of 0x00000080 (0x00000000 0x00000000)

I have checked all the Microsoft XP support articles and I
have not been able to see the above error message.

Any help will be highly appreciated.

Thanks

 

[Robert Norton]

Here's the description of the error message from Windows Inside Out

"This message indicates a serious security problem with Windows XP—a
user-mode subsystem,
such as Winlogon or the Client Server Runtime Subsystem (Csrss.exe), is
compromised. The most common
cause of this problem is a third-party program, and the solution is
usually to remove that program.
This error can also occur if a backup set has been partially restored,
causing a mismatch in system
files, or if system permissions have been incorrectly modified so that
the System account no longer
has permission to access system files and folders."

I suggest you do a repair install of Windows XP to get your system files
working again!