I have a Win 2003 Svr Std, DC that came up missing its NTOSKRNL.EXE last night. After much troubleshooting in the Recover Console to no avail, I performed a Repair of the operating system. It went without incident and completed successfully. It is broadcasting DHCP, DNSing, and everything else its supposed to do, including replication with the other DC's. However, when I go to login to it, it accepts the domain administrator username and password, and it logs in and at the very same moment logs off and takes me back to the Ctrl-Alt-Del screen to logon.
I can manage the server in computer management from another of DC's, but cannot login to the server itself.