hello

every few hours i'm getting a dialogue box that tells me my machine will restart in and when i check the event log aferward i get this Winlogon error: Acritical system process lsass.exe C:\windows\sys32\lsass.exe failed with status code128 and the computer needs torestart. i am totally vexed and it had become a nightmare on my box which has Win Server 2003, Mdaemon and apache running.
My email clkients are all complaing becoz it can reboot anytime.

Please please help i have googled this problem and can't find anything. I dont think its the Sasswer virus becoz all cleanup tols i've used have failed to pick it up.

thanks in advance

Chichi