Installed the game yesterday, launched it straight from the installer, everything went fine.
Tried playing again today, but somehow the game won't start properly. It launches a DefendersQuest.exe process that grabs 108k ram and then nothing else happens. Task manager is unable to kill these processes, got 4 of them running right now. Rebooting gets rid of those obiously, but I still can't launch the game afterwards.

I have absolutely no idea why this is happening. I could play for hours yesterday and as far as I can tell nothing on my system (win7 64 btw) has changed since then. Is there a logfile hidden somewhere that might tell me whats up?

Thanks, looks like that did the trick. The shortcut already had "run as admin" set under compatibility settings, no idea why that one didn't work. Anyways, game started up fine with "right click => run as admin" and as long as this keeps working I don't really care.