windows server 2003 security problem

I’m an administrator who a little bit novice in windows enviroment.Someday ago I tried to backup my server by “Acronis echo enterprise”. after creating ASZ completed my logon screen came up and i typed the admin pass but it was rejected by this error:” The local Policy of this system does not permit you to logon interactively.”
I did change nothing to my policies and i wonder why this happend to me. the only thing that i think it’s my fault is: I created the ASZ from my C partition. I tried ERD to make a user or change a user’s group membership by the command line, but actually there’s no success because of system’s permissions. any suggestion how can I solve this?