How to create screenshot picture of a video file?

Hello experts!
I had a homemade video file taken from a digital camera. It’s a Family outing video about 75 minute length. I want to create a picture files or screenshot of some part of the video. I would prefer to have it by reviewing back the video and just by clicking, I can have a screenshot or a picture file of what I want from the video. I’m running in a win7 OS.Please help.
Thank you!
