pause the film where you want to take the screen shot. then click on full screen button...then click on the PrintScreen button on your keyboard ( this copys the picture to your windows clipboard )
note: you do not have to always open it to full screen, sometimes you might want to show the film info on the right side. you can still just pause film and click print screen......
then open up any paint/photo program- MSPaint, Paintshop Pro, photoshop etc..and paste into a new picture file and save........