File Renamer Ultra 2000 (originally called "A Program That Renames A Whole Bunch Of Files At Once") was a commercial product developed by me and a friend from 1998-2005. My military deployments and my friend and business partner cleaning the business account and disappearing led to the demise of this enterprise.
Since then, I released FRU2000 as freeware with the registration mechanism removed.
There are two archive formats: zip and PowerArchiver (*.pa), choose one. The instructions to install FRU2000 are contained in the archive file. Runs on Windows 9x through 11. Rated FIVE COWS by TUCOWS!
Original site mostly preseved by the Wayback Machine: https://web.archive.org/web/20050305210507/http://www.techalchemy.net/index.html