Rename

Hello all i need a file that will rename a exe file with .old at the end for every exe file on the computer, I had a file below as a test for one file, but need it to rename the file to .exe.old without changing the file name ie. test.exe.old, thanks.

@ECHO OFF

ren “C:\Documents and Settings\tm09042\Desktop\test.txt” “test1.txt”