computer can't log on Windows Server 2003

[drvic10k]

i have a problem, we have a workgroup network with Windows Server 2003 server, 20+ computers with XP and Win 7, none has problems, but one
yesterday, we had several power cuts, which may or may not be related, as all other computers work fine

this computer can see the server on the network, but can't log, the password is not accepted, i tried different user names, no success
this computer can connect to other computers on network and others can connect to it

do you have any idea what can cause this problem?

thanks for reply, Matus

 

[drvic10k]

problem solved

the system date was changed manually and this caused the problem