Problems with domain removal

Hi,
I have a network with domain,NT server, and 3 PCs XPPro. Now I have to pass the 3 PCs to a new network organized as workgroup with Win 2003 Server.
On one PC I have changed the setting from "Member of Domain" to "Member of Workgroup ", but when I restarted the PC I am asked username and password and the originale values are no longer recognized as valid, not even if the PC is not connected to the network. Therefore there is no way to access XP.
Any idea? Can someone help me?

 

Did you remove the original user account after joining domain? If yes, login as Administrator and create a new user account.

 

The problem is that I cannot even have access as administrator, perhaps because a password has been set but in this case nobody konws the password. Is it advisable to use a utility to reset the password? In the positive i am looking forward to your suggestions about the utility to be used.

 

The easiest solution I have heard about for such cases is to boot with Win2k CD & then reset password. You can try that.