Advice?

My laptop is like, terrible.
I have NO CLUE where my mom got it, but it is really crappy. :I
The right mouse button doesn't work.
And my main problem that I need advice on: The print screen button doesn't work! D:
I'm in need of a program that allows you to take screenshots, but, I don't want to pay for it, nor have to remember to delete it and renew the trial again.
So if anyone knows anything, it'd be much appreciated. I like to take screenshots of things.