If you have a video file in avi, mpeg or wmv format, as well as another type of video from which you want to save a certain frame, ImageGrab is the right program for the purpose, which does not even need to be installed.
After selecting and launching the video file, you can save the frame as an image or directly to the clipboard.
It supports many formats – from classic AVI, MPG and DVD to modern MTS and M2TS.
License: Freeware for non-commercial use.
Download: ImageGrab 6.3.0 (11.2 MB)