Usenet Explorer

I remember Alex told me where it was about 4 years ago but I'm getting old and can't remember.

In reg.dat in the Settings directory, but it may be in a random location in the file, try to append some word to the existing password in edit menu->properties->servers, then exit UE and look for the word in the binary editor (back up reg.dat before modifying the password in case you'll delete the original password accidentally).