Recently working on a File/Print server (that was also a backup DC) and began to receieve the following error from client PC’s trying to access it –

Login Failure: the target account name is incorrect

Most google posts seem to refer to checking DNS/WINS settings although in this case everything was fine. I could access the shares via \\192.168.xx.xx but not \\servername. Looking in to the error further there were some error logs referencing kerberos issues and the main clue was found after running netdiag. The netdiag report came back with the below error –

[FATAL] Secure channel to domain ‘MYDOMAIN’ is broken. [ERROR_ACCESS_DENIED]

So if your having a similar issue then it’s usually a case of resetting the machine password via the netdom tool. If it’s occuring on a workstation you may want to just remove it from the domain and add it back on, however if a server has the issue then this Microsoft article will help –

http://support.microsoft.com/kb/329721 (Description of netdom.exe Syntax and Versions)
http://support.microsoft.com/kb/260575 (How To Use Netdom.exe to Reset Machine Account Passwords / Domain Controller)