It is so much less complicated than anyone even knows. All you have to do is start the game, go to your task manager > Processes, find pnkbstrA and pnkbstrB, right click on them. Select "properties", then click the compatibility tab. Select "run this program in compatability mode for vista sp1. You are done. Enjoy the game.
There is absolutely no need to hack registry files to make it work.
I have many installs of both 32bit and 64bit, and this works on both versions with CoD4 and CoD5 both.
I wish it was that simple mate. And besides they are services arent they?
I wrote a piece of powershell that keeps resettign the reg entry for pnkbstrb service.
"HKLM:\SYSTEM\CurrentControlSet\services\PnkBstrB\" -Name "Type" -Value