Q: i've looked through all my picture files and cannot find it.
A: On Windows, you can use shift-printScrn to take a screen shot of the entire screen or alt-printScrn to take a screen shot of the window. The screen shot is on the clip board. So you launch Paint (Start:Accessories:Paint) and choose Edit:Paste from the menu to put the screen shot into the paint program. You can then use the selection tool bar to select polygon and then square again. Then select the part of particular interest. Use Edit:CopyTo to save what you have selected to a file.