You will need a video editor in order to crop the borders of the videos that you have in your computer. For example, I've tested VSDC Video Editor and it worked very well. I was able to crop the borders of a video I had stored on my hard disk.
To crop the borders, simply load the video and access Object menu or Object properties then select Crop Borders. Once you've selected that option drag a square inside your video and adjust the margins as necessary using All, Right, Left, Top, Bottom orientation and that's it.
