There is a
Snipping Tool built into Vista/7 for taking screenshots. I've used a program called PNGShot, but have not looked at anything else recently (a few I've seen mentioned, and may check out someday:
Greenshot,
Jing,
Hypersnap,
Gadwin PrintScreen and
MWSnap).
You could also just hit the Print Screen button, exit or alt-tab out of the game, and paste the results into an image editor / viewer.
IrfanView is (primarily) an image viewer, which can crop and do simple edits. Actually, wasn't the Windows Paint program updated a fair bit in Windows 7? If Paint will not let you save as jpg, etc, and you don't want to install anything, there are
online photo editors.
