SOLVED
Hi everyone,
Problem is not with a video card and is has nothing to do with video drivers. I think it has something to do with a motherboard.
Before this solution I tried everything - renewing video drivers, deleting windows updates, I even installed new system coolers, tested random memory for errors - nothing helped.
I have Gygabyte GA-MA78G-DS3HP. What you want to do is download latest mother board drivers from GYGABYTE site:
http://www.gigabyte.com/support-downloads/download-center.aspx?ck=2
I don't now about the other models, probably you can find something similar on google.
I'm not sure which one of them did the trick, I recommend installing them all - chipset, audio, networking, it never hurts to renew your system drivers.
Finally after 6 months of crashing I can finally enjoy full system performance. Good luck.
Congratz! Unfortunately this is just one scenario why you would receive TDR crashes. Other people have already tried this solution with success, and some with no success. So I wouldn't say it's "solved", due to the fact that so many different factors cause
this problem.
But thanks for sharing, hopefully this resolves the problem for someone else too!