Game won't start

Hello,
for a couple of months now I wasn’t able to normally start Heroes, and I’m getting tired of it. The thing is, i open battle.net, start the game and it just doesnt start. If you stay and wait, after 15 minutes Heroes will ‘start’, but it’ll be all black and not responding. What I always have to do, after launching the game i restart my whole computer, start the game again and then it finally opens. I’ve tried re-installing the game, scan and repairing it and it doesn’t work. Can someone help me out, or point out the problem? Thanks.