Make sure you have windows live movie maker downloaded onto your computer (it's free).
Open movie maker, then look at the 'open' options - it will give you the option to browse to your video files and open them. then when they have loaded up, you'll see 'rotate' options on the top command bar. Click until you get your movie the right way up. Then go to 'save' or 'finish movie', have a look at the options and choose the one you want.
Done.



