Change file extension of all files to the one specified

ChangeFileExt.ahk

;Used to change ALL files in a folder to become a specified extension and to a new name followed by an incrementing number.
;It's been handy to use sometimes when software hasn't outputted a series of files correctly but manually renaming them would fix them.

;What name shall we give the new files?
NewName = picture
;What should their extention be?
Extention = .png
;Warning that this isnt an undoable action.
msgbox,4,Warning,This will rename and change ALL files to %Extention% in the current folder`nThis is not undo-able.`n`nDo you want to continue?
ifmsgbox,no
  exitapp
;Used by the below loop to determine the picture number.
number = 00
Loop * ;Run command on every single file on this folder.
{
	if A_LoopFileExt != ahk ;But don't run it on .ahk files
	{
		number++
		Var := SubStr("00" . number, -2) 
		FileMove,%A_LoopFileName%,%NewName%%var%%Extention%
	}
}