Hello all.I have a radeon hd 5770 gpu.I used to play games with it.Suddenly a couple of weeks ago i was playing game & my display freezed up for a minute & turned off.When it turned on itself it was black & pixelized.the numkey was still on & wasn't goin off as i pressed the numkey to understand if my system was even posting.It wasnt blinking.But my whole system was on.The fans were running & the hdd led on my case was blinking as well.Every time it happens I had to forcefully restart my pc with the reset button.Nothing works other than that.here is the video of the problem --- https://www.youtube.com/watch?v=5D7UVBF1bxQ . Then i googled fro some solution & i updated my drivers,even changed the regedit (tdrdelay value from 2 to 20). but the problem persists.It only happens when I play games.My temps are really fine though.I checked the ram also with memtest.Stressed the cpu & the gpu.Evrythings well.& from last 2 days after this problem happens i have started to get a notification in the notification area saying application has blocked from using graphics properties.Please anyone show me a way.