how can i watch a downloaded movie on a DVD player?

Some players don't have mp4 codecs installed.
You can try to upgrade the firmware, but I don't recommend it.
Instead, convert the video to avi or mpeg.

You have to convert it into mpeg

you have to convert it to dvd format, vob. you can download software to do it, but if you are using vista you can use windows dvd maker. its really simple and easy to use.

To be able to watch movies on a DVD player, you need...

1. a DVD-RW or DVD-R drive that can burn to dvd's.
Cd rom drive can't do that.

2. A DVD-RW or DVD-R disk to burn the movie/video file to.

3.Then download a third party dvd burner program. It's easy to find on the internet for free.

After you burn the file to the dvd disk you can watch it on a dvd player.
Don't drag the file onto the disk.