user profile not listed in Win xp

Hello, I have a computer that has been recently updated
by a contract company. the problem now is that the user
of this computer has been logging in under a user name
she set up when she got the computer. She still is able
to use that log in name, but when we went to set up a
password for that login, I could not find that user
profile anywhere. The company did set her up with a
different login profile, but it currently does not work
properly.

is there any way to find this missing profile and modify
it correctly?

any ideas, tips, tricks, whatever, would be greatly
appreciated.

Rob