I suggest that you try this. Do a search for *.pwl (password log) Change the extentions in case it all gets pear shaped. Delete the pwl file(s) and reboot.
It should start by asking you if you want to setup a Windows login password, etc. It should be like starting with a new file.
If, for some reason this doesn't work; boot in the DOS mode and change the extentions back to pwl.
Unless there is something weird in your setup, it should work.
Good luck.