Is there a way to cut parts out of a WMV or picture files?

I like to screen record certain parts of computer games and videos that I find online. However, when I screen record, it shows the rest of my screen that I don't want. I am asking specifically, if there is a way to cut out the extra parts I don't want. Also, I can take screen shots and make an album out of them in a row, but they also have extra parts I don't want. I don't want to go through each picture and edit them because it would takes hours of time. Is there any option to cut them all down to size at the same time?