mass posted one a while back...it's a combination of a batch file and a vb script......im sure there are more ways to do it, but his way works....for internet explorer any way....
http://www.ss64.com/index.html
has lists of commands for most major os's....basically all you have to do is come up with an idea, then find the commands that you would need to use to make the idea work......
ie: if you wanted to change the contents of autoexec.bat so that on startup your file was excuted that you coppied onto their computer you could use:
@echo off
echo start blahblah.bat >> c:\autoexec.bat
then the rest of the code....
(me thinks....probably wont work on nt or xp computers....i no remember if autoexec.bat even exists on later os's by microsoft...)
just be original, stop asking us to do everything for you....