I had to move a computer account from one OU to another OU for the settings to be same as with other computers in the OU. After the computer account was moved to other domain, i reset the computer account. Now there is no domain access to this computer even using domain admin acccount. The error message is that windows cannot connect to domain because your computer account was not found.I reset the computer account again and that didnt make any difference. Local admin access was possilbe and i tried to change the computer to workgroup to join back to domain, but workgroup changing option is greyed out. Is there any way I can solve this issue. Thanks in advance.
Resetting a computer account breaks its connection to the domain, so it makes sense that a domain account would not be able to log in: http://support.microsoft.com/kb/216393
As for unjoining/rejoining, try running
netdom /joinworkgroup - that should remove the computer from the domain - or at least give you a more descriptive error message than just being greyed out.
NetLogon service is probably not running. Possibly your
workstation service as well. Check that they're both started:
sc query netlogon sc query workstation
If one or both are disabled, enable them:
sc config netlogon start=auto sc config workstation start=auto
Then, make sure that they're started:
net start netlogon net start workstation
Try to join to the domain again.