Rotating digital movies

Hope someone can help with this...

A couple of my movies on my Lumix have been taken in the vertical position - silly me. I have downloaded them onto the computer and put them on CD but cannot find a way to open them with the individual frames so that I can spend time reversing each frame thus making the movie horizontal. Is there a way?? I have googled but come up with zilch.

Hubby suggested putting the tv on its side when viewing - he'll be out of hospital in a few weeks

Any suggestions gratefully received.