external hard drive to tv?

[C-LO]

Ok i have a philips flat screen i want to get a external hard drive so i can transfer all my movies and music to the external hard drive and still be able to watch movies on the hard drive. my tv does have a usb and i put a movie and some music on a flash drive and put it in the tv the music showed up but not the movie does that mean my tv don't support movies through the usb because when i plugged it a screen popped up on the tv besically it picked up the flash drive and the screen said pictures or music so a external hard drive will not work for movies or is there is a certain format for the movie to be i tried avi and wmv if not what can i use to get my movies off my computer on a external hard drive and be able to watch them on my tv i need a list of devices that will work for me please