Windows 7 problem

I'm having a password problem. setup is two xp computers, one window 7 and server 2003. xp and win 7 are home edition. the xp computers no problems connecting to server, but win 7 when I try to connect it tells me that the user name/password are incorrect. I can connect to the xp computers through win 7 just can't connect to the server. Everything was working fine until yesterday when a power outage occured. restarted all systems and windows 7 is the only one giving me problems.
what I have done is:

check the settings on the server for the win 7 computer everything is just as it was set up.
reset password anyway.

on win 7 computer check to see if the file sharing password was turned off. It was
did a system restore.
checked the registry for the lm compatibility level is set to 1.
verified that I can connect to the other computers no password required.

The other computers connect to the server just fine. (windows 7 is the problem).

any help would be greatly appreciated.