Back in Hw came out i had the same problem, i would dc and not be able to connect to the game, i weeks of problem dc all the time and i was really angry because i did not have any trouble in arr.
What i found out from this site that the DX11 version of the game was not allowed through windows firewall, i let it trough and i had no more dc.
Why did it work in arr and not hw, well that was because that dx11 version of the game came out with hw, so i enabled that.

Hope that fixes it