Screenshot Issue & CO2 Issues

[CapnScurvy]

Taking an in-game image with the Ctl+F11 key combo is normal, so is the name the game gives the .bmp image, and the placement in the game's "main" Silent Hunter Wolves of the Pacific folder. All stock game functions. The 3Mb size is about right too. Don't worry about cut/paste in the folder, if you use the JSGME "Compare Snapshot" you'll have those image files as "New" found files if you don't remove them.

Why the image isn't openable is an issue more likely due to your computer. When you right click the .bmp, do you have a choice of "Preview, Edit, Print" at the top of the menu popup? Can you take the image to any of these functions? I don't have Windows 7, but I'm suspecting there's something fishy about your "Windows Picture & Fax Viewer" (least that's what its called on older OS systems).

As far as the "Co2 bug" (yep, we have a name for it).....
its a stock game problem many of us have encountered. Here's a recent thread...."Co2 Bug"....that has a lot of opinions on the subject. Nothing we can really do about it, just have to work around it.