windows 2000 server error

hay friends i am having a serious problem with windows 2000 server. when booting up it shows the following message

"lsass.exe-System Error: Security Accounts Manager initialization failed because of the following error: Directory Service cannot start. Error Status: 0xc00002e1. Please click OK to shutdown this system and reboot into Directory Services Restore Mode, check the event log for more detailed information."


and the system restarts.this is the back up server of the network and all clients are connected to this machine.
plz help me

Sounds like it could be a virus. Boot the machine into safe mode, run a virus scan, clean the virus.

Or try the suggestions quoted below:

Quote:

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Uh, I could be wrong, but I thought that Isass.exe was a system file for
Active Directory. Be sure that your DNS address is the IP address of the DC
when you install it. That's how I screwed it up. seahunt
***

lsass.exe - System Error : Security Accounts Manager initialization failed
because of the following error: Directory Service cannot start. Error
Status: 0xc00002e1. Please click OK to shutdown this system and reboot into
Directory Services Restore Mode, check the event log for more detailed
information.

(Last update 10/21/2003):
This issue can occur if the path to the NTDS folder that holds the Active
Directory database files and log files does not exist or the NTFS
permissions on this folder and database files are too restrictive, and
Active Directory cannot start. See Q258007 and Q295932 for more details.
Also check Event id 26 from source Program Popup.

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Last time I had this it was a faulty hard disk try booting from the install disk into recovery console and running ChkDsk /R on the boot and system partitions (if different). If that gets you going again then clone the disk and put the new disk in it's place. You should always have disk mirroring/duplexing on essential servers. LSASS is the local security administration sub-system.
If you have just been changing security settings then take a look at http://www.jsiinc.com/SUBF/Tip2500/rh2599.htm