@Mr-Android I found a fix for myself out of anger, I put plutonium on my desktop and spam clicked plutonium, a bunch of cmd windows popped up over one another, until eventually one worked and opened up the launcher and i was able to start the game. opening all the cmd prompts didnt lag my computer, so i think anyone having this problem could try it, and when the launcher opens close all the other cmd prompts.

@Mr-Android its turned off, still nothing.

@Mr-Android Comcast, also I've tried running in administrator, still nothing

Im having the same problem, I've allowed MW3 dedicated servers and plutonium through my firewall, didnt change anything, Real time protection is off, Ive tried to restart steam and my computer, Also tried reinstalling plutonium and MW3 dedicated servers, still same problem