From my experience you cannot actually get your old profile back. I had the exact same problem on a Windows 2000 machine.
However, you can still regain all of your files and settings. What you should do is login to another account that has administrator rights on the computer. You can then rename your old username folder / profile to something else and delete the temporary profile that was created after the corruption.
You can then log off and logon as your username (the one with the corrupt profile). It should then create a new folder / profile in the Documents and Settings folder. You can then log off and logon as the administrator (as in the first step). You can now copy all of the files and folders from the old profile folder to the new one.
No more corruption, and all your files and settings are usually intact.