lsass.exe system error

on boot after wi xp loading screen i get the following message:

lsass.exe system error

indicates a revision number encountered or specified is not known by the service.
It may be a more recent revision than the service is aware of.



click ok and it repeats in all boot modes.

tried repair install same result
microsoft site was no help

"lsass.exe" is the Local Security Authentication Server. It verifies the validity of user logons to your PC/Server. It generates the process responsible for authenticating users for the Winlogon service. This process is performed by using authentication packages such as the default Msgina.dll. If authentication is successful, Lsass generates the user's access token, which is used to launch the initial shell. Other processes that the user initiates inherit this token. More info

Note: The lsass.exe file is located in the C:\Windows\System32 folder. In other cases, lsass.exe is a virus, spyware, trojan or worm! Check this with Security Task Manager.

Virus with same name:
W32.Nimos.Worm - Symantec Corporation
W32.Sasser.E.Worm (Lsasss.exe) - McAfee
W32.HLLW.Lovgate.C@mm - Symantec Corporation

yes yes deleted and replace that lsass.exe from the cd, still same error

possible virus or trojan?