MW major lag issue. Help Please

[Andriy242]

Alright so I finally got MW and started playing it.

Set it up and it worked like a charm on the settings that were in game and the game had 0 lag and not even a freez or anything. It has been running great for 2 days. Now here is the odd issue.

Played the game last night, and then turned it off and went to bed.
Got up today and the game lag majorly. Like its running at 10fps, Even if I run it at 800x600 with everything off it still runs to shiznit.

I have tried locking the FPS to 30 but that doesn't help and I have nothing running in the background at all.

Computer specs shouldn't matter now since the game ran for 2 days. But here they are anyway.
i7 3630QM running at 2.8
8GB Ram
Radeon 7870 2GB DDR5

So that definetly is not an issue. Help me out if anyone knows how to fix this