Windows 7 - mass file extention renamer?

just wondered if anyone knew of any software out there that would rename a bunch of files... specifically a batch of extensions rather than me having to do it one at a time.

lm pretty sure it can be done via the command line. but is there a program that isnt riddled with spam that can do it?

Open the folder that you want to change the extension in, hold down the shift key and right click in the folder choose Open command window here and use ren
here is an example
ren *.png *.jpg this would rename all .png to .jpg in that folder just change the extensions to your liking.
This article may help Batch Change/Rename File Extensions In Windows
Jerry

Also FreeCommander has an easy to use multi rename. Select the files you want to rename, hit F2, then change the extension. Has placeholders for name extension number. Easy to number files 01 02 etc.. It's somewhere between Explorer and Bulk Rename Utility as far as functions/ease of use trade off.

One of the tutorials on this page shows how to use it:
FreeCommander - freeware file manager