I mostly make mistake of recording rotated videos using my
phone, so I end up seeing a lot of my videos on my pc while my neck is tilted. Luckily VLC
media player has an option of rotating videos while they play. First you need
to download VLC media player from http://www.videolan.org/vlc/index.html, it’s completely free and supported for all platforms: Windows, Linux, Mac OS X and Unix.