When I first bought DayZ, I downloaded it and tried to play it, but I couldn't. When I launched DayZ through steam, my laptop's screen turned black as if the game was loading then after a few seconds, it crashed. So I decided to re-install DayZ. I was able to play for 2 hours, then, I turned my laptop off. The next morning, I opened DayZ to play but the game crashed again. So I decided to re-install steam and DayZ but after re-installing, the problem did not disappear.

IMPORTANT: I tried to run DayZ as an administrator and it said "Unable to locate a running instance of steam" AT FIRST. For some reason, that message is now gone even if I run DayZ as an administrator. But I still cannot play the game {F30803}