PC software needed - rotate 90 degrees

Yes, I used a digital camera in movie mode and now have 1GB of .MOV files which give me a real crick in the neck!
I didn't want to put the good cemera out the top of the car in reach of the flies, stones, rubber and rain.
The only mount I had available was a sucker mount for the window, which put the camera in Portrait orientation instead of landscape.

So what I need is to take fixe .MOV files and rotate the movie images 90 degrees!
I found Microsoft-in-the-head movie software trashes the aspect ratio.