Shutdown instantly and Microphone help!

Dear users/mods!

I’ve bought the game on 18/12/13 and the game was worked correctly for 3 weeks. Since the new update has come out the game makes instant shutdowns. I can play for 5-10 minutes then the computer shutdown. I don’t know what’s wrong with the game but this is the only game that makes my computer to shutdown (instantly). I’ve tried to reinstall it but that didn’t help me. I’d really like to play the game again. I hope somebody can help me.

My computer details:

Processor: Intel Core 2 Duo 3GHz
Memory: 4096MB RAM
Video Card: NVIDIA GeForce GTX 760
DirectX 11
OS: Win 7

My other problem is the microphone. I’ve got a Logitech Wireless Headset and in the game nobody can hear my voice. In Skype my friends can hear my voice, but in the game nobody. So I have to attach it to the game, or what? I found nobody who has the same problem, that’s why I’m asking you guys. I hope again somebody can help me.

Thanks in advance!