W2K registry cannot load hive file

Hi,
I have a client that had his pc lock on him. He inplugged and then tried to reboot and now gets blue screen error message ” The registry cannot load its hive file systemroot\system32\config\software or its log or alternative is corrupt or unwritable. I do not have a ERD disk for this machine. I have run chkdsk /r from recovery console but it did not work. Any suggestions?