Well, if you use a PC with windows, it should have a free program called Windows Movie Maker. Its under Start->All Programs->Accessories and possibly-> Entertainment. Once you open the program,you click "Import video" and find the file. After that the file will show up in the big white space, and you drag it down to the timeine. Then, to crop parts of it, you click on the right end of the video on the timeline, and drag it back to the time you want to crop it at.
Then, you go to "Save to computer" on the side bar on the left (I think.) That should work. I haven't used WMM in a long time,though. So I could be wrong.
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