*sigh* There is nothing wrong with my PC, or the installation. It is the patches. You see, it works perfectly fine without the patch. I can play signle player all I want. Multiplayer requires the patch. I download the patch and: Wrong Disc Inserted. It's the patches problem, not mine. I know a lot of others that have this problem. Is it because I have the DVD version? I don't know. Petroglyph need to make a fix. I called activision and they said they have had a number of people with the same problem. So FIX IT.