http://www.robpol86.com/Pages/imagecfg.php' ">http://www.robpol86.com/Pages/imagecfg.php

Follow the instructions there. It's simple as far as savvy computer guys go. If you need a hand, ask!
It IS a command interpreter text-only tool. It CANNOT perceive spaces within file pathings, so you must encapsulate a path to a file with open and closed quotes (" "). Alternatively, you can copy the executable to each game directory, run it against your game file, and then delete it afterwards.

Also, if the first -a 0xX command doesn't work, perform the -u pathtoexecutable first and then redo the affinity setting command. Remember your quotation marks!