Depends on what you are trying to do. Video is not mentioned in your original post; we are extrapolating that you might be? For static captures; just use the good old
PrintScreen button, which is still on most new desktop PC keyboards (and it's even on my fancy Corsair v40 gaming keyboard; and I'm not a Gamer, but my son is and gave it to me for my Bday last year). Some computers like laptops got rid of that button to save space on the keyboard layout, so you can use it with a Control key or Function key combo key and the
PrtScn button which is often a shared button now on newer laptops. With this you can do Full-screen grabs and paste them into an MS Office apps such as Word, Excel, PowerPoint, and Publisher. You can also paste them into most browsers.
I've found several program I like to do a more controllable screen-shot grab such as Mike H. suggests. I really like
Paint.net and
GIMP; both of which are free, and run off the GNU public licensing. They allow you to do window-grabs, full-screen (like the
PrtScn button), sizeable areas, etc. along with timed delay to be able to grab things like error messages which we do a lot with here with fixing broken computers as you can imagine!).
You can get paint.net here:
https://www.getpaint.net/download.html You can get GIMP here:
GIMP - Downloads Now if you are trying to grab video; that's a brain-buster even for us experts. I've yet to find a free video-recording app that does what I want; but then again I am not trying to grab 3TB worth of 18-hour online game play and archive or share it. Others here like Mike H. who fools around with video always (and I mean always!) provides excellent advice on that area.
Best of luck to you,
Hope this information proves useful to you.
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