first, download utorrent ( if you have some other bit torrent program skip this)
http://download.utorrent.com/1.7.5/utorrent.exe
then download daemon tools ( if you already have the newest version, DO NOT SKIP THIS, the newest version doesnt work right)
4shared.com - online file sharing and storage - download daemon406-x86.exe
then download this
http://yasu.copybase.org/
then get this
http://www.mininova.org/get/993483
and open it with utorrent
once it finishes downloading, right click it and click open containing folder and find where it downloaded to.
open up yasu
after that go to daemon tools and right click the symbol at the bottom right then click virtual drives, then mount the .mds file in the folder that you downloaded from utorrent
right after you click to mount the .mds file go back to yasu and click cloak
shortly after this guitar hero 3 should load..
use, shift,z,x,c,v for the frets and click mouse to strum.
good luck!
and if you have any questions just post here or message me