User Account Windows log in problem

I am migrating my workstations to my new domain. All computer names and user’s accounts have been setup in my active directory. After I re-install the workstations I can log in using administrator account. So I installed all necessary software applications and it was successfully installed. So to check if there are no problems with the users accounts, I logged off the administrator account. But when I log in to users account, it won’t log in.
The message said that, “the user name cannot be found. Make sure the Domain and User Name is correct. Check also the password if it is correct". I cannot give a screen shot due as the error is outside the Windows.
What seems to be the problem?
