Busted SAM

Hi Guys,

Hopefully someone can help with this one.
Unable to login to 2003 server with DHCP, DNS and the server is a DC. Unable to login VIA domain or local machine (using default/bluit-in Admin account) states the username or password as incorrect.

Removed password using SAM password removal tools, does not resolve issue.
It appears SAM is corrupted, anyway to fix this and log back into 2003 server without losing any data (I would hate to have to restore from TAPE library as this will take a while)

Any comments/suggestions will be greatly appreciated, Thank You