Originally Posted by Slaz

Windows 8 got the honour of being the first Windows version that fundamentally broke parts of JJ2, without including the XP (and later) theme models not going well with JJ2's window captions. Basically, the game works just fine yet there are 2 strange problems.

1: A major video performance loss occurs while using fullscreen, Hardware Mode slows it down even further! This is not exclusive to JJ2, but will happen in any game on Windows 8 utilizing DirectDraw in combination with either double or triple buffering. The hardcoded -notriple flag thus doesn't work as there'll be double buffering instead. So far Microsoft support reps have ignored the issue saying 'DirectDraw is an old technology that should be avoided'..

2: Network connectivity (netcode?) will be lost when switching out of fullscreen during an online game (not in the menu). This doesn't happen if you enter an online game windowed and switch to fullscreen from there. If this happens, you can only get connectivity back by closing and restarting JJ2.

I don't think there's an easy way to fix issue 2, as I don't understand the actual cause. Hence, the best workaround for us fullscreeners is to not switch out of fullscreen while playing online. For issue 1 however, I found this good yet clumsy workaround, so let's just quote myself from the Windows 8 thread: