When I launch GOG Puzzle Agent 2 my screen goes black as if it's launching in full screen, then it minimizes. If I click it again in the Windows taskbar, it comes up for a second as if it's going full screen, plays like a quarter of a second of the intro movie, then immediately minimizes again. I don't suspect many people are in the Puzzle Agent 2 forum these days. I'll update this thread if I figure it out.

On the same computer, the Steam version of Puzzle Agent 1 works fine (which seems very similar, same intro movie, etc.)

I've tried compatibility mode for Windows XP SP3 with no luck.

Edit: Compatibility mode for Windows 7 actually worked. I ran the compatibility troubleshooter and it chose that automatically. This is the first time the compatibility troubleshooter has both chosen Windows 7 and the first time I think it's actually fixed my issue. Wow.