Jackass JoeJoe's RenameMaster utilities was a utility I came across when I had to selectively rename about six hundred HTML files within several thousand - no leading zeros on files numbers below ten. This made it a breeze and I normally pride myself on being able to do anything through a command prompt! It also has great rename options for MP3 and JPEGs (can stick in all the metadata you can discover) - a must for webmasters and folks with big music collections everywhere - and it's free!.