I had a issue with vista where there was an issue where I changed some network settings i.e. joined a new workgroup this caused a problem with some legacy software (funny that). The login process on the laptop never had any passwords i.e. just logged in. When I rolled back 5 days using vista system restore the machine boots now asking for a password. Never had login screen before for password when I issue a blank password it asks to "contact network administrator". I now cannot log into laptop.