Download and install Windows Live Movie Maker (please see the Resources section). Open the free program when the installation process is complete.
Click the "Add videos and photos" button, which is at the top of the screen. Navigate to the video file you want to rotate. Select the video file and click "Open." The file will be imported to the program.
Click either the "Rotate left" or "Rotate right" button (both are at the top of the screen).
Download and install Free Video Flip and Rotate. Open the program, which is indeed free, when the installation process is complete.
Click the button to the right of the empty box, under "input file." Navigate to the video file you want to rotate. Select the video file and click "Open." The file will be imported to the program.
Click one of the seven flip or rotate option arrows at the bottom of the screen.
Download and install VirtualDub. Open the free program when the installation process is complete.
Click the "File" button at the top of the screen. Select the "Open video file" button from the drop-down menu. Navigate to the video file you want to rotate. Select the video file and click "Open." The file will be imported to the program.
Click the "Video" button at the top of the screen. Select the "Filters" button from the drop-down menu, then the "Add" button on the right side of the screen.
Select the "rotate" button from the list. Click "OK" on the right side of the screen. Click the circle next to the degree to which you would like to rotate your video, then select "OK." Your choice will be added to the Filters menu. Click "OK."