Hello,someone pls help me...I custom build my pc system specs are: mb asrock z97m anniversary,ram hyperx fury ddr3 1866mhz,cpu intel i5 4690k,psu chieftec navitas gmp 1000c-1000w....all parts are new just buy from store...and gigabyte gtx 690 used(think its culprit) and all is working on windows 8 x64 nvidia driver 344.75 whql!!!Now to probles....system boots fine,log in account(random system crash with black screen,can get back only with hard reset) windows works fine,can using net,watch youtube,listen to music....but when try to run some game,than immediate black screen crash with no error report,try furmark....the same crash after 1-5sec furmark render,cant even open geforce expeience...immediate crash!!!What a problem?Swap 690 with 680....everything works fine!igpu works fine!Try windows 7 x64....the same,but few times see error code 7 something about opengl and driver stop responding....but in windows 7 I can run furmark only on windowed 640x320!!PLS HELP ME!!!!