That's strange. I run on Win8 and the fix linked to above works just fine for my vanilla CoD install. (A common mistake is that people don't create a shortcut to the CloDer launcher and run the game from there, they just install CloDer and run the game from the default shortcut, which doesn't work. You need to run CloDer to call the game properly.)
If that still fails...unless you really want to go the dual boot route, the Team Fusion mod also runs on Win8 without needing any special Win8 launcher. So you could just try installing the TF Mod and see if that does it.
(For example if you already have Win8 installed I don't think you can go back and create a Win7 dual boot from Win8. You have to go back, completely blank your HD, install Win7 first, and then the dual boot to Win8, which is a mega pain.)
Fred