Lets us say you have just download one of your CDs to your computer and all the files are .mp3 and you need them to be zip's, rar's, mp3's etc.....
I will show you how you can bulk edit them by doing the following
-create a new folder "C:\Files" For example
-put all the files needing editing in the C:\Files folder
-then goto "run" in the start menu
-type in CMD and click ok
-you need to navagate CMD to the folder whree the files are
-Now we are in the folder we can now do the bulk rename command
-We have have just renamed every file from *.mp3 to *.zip
-You can change the file extention to what ever you want, It doesnt have to be .zip