Cannot playback movie downloaded from itunes from external usb drive

Hi,

I've just purchased an downloaded Avengers Assemble from the itunes store. I wanted to play it on my new external 42inch LCD TV.

I thought if I moved my purchased file to an external USB drive I could connect this to the TV and play it back from there. This doesnt work.

Is it because the movie I downloaded copy is protected? All I want to do is watch it at home on my big TV. I feel i've just wasted £13.99.

I also tried viewing it on my TV by using the DNLA network. I connected with my imac and I could see all my movies on there apart from Avengers Assemble.

(My TV is a Panasonic Viera TXL42E5B)

Please tell me there is a way I can watch my download without having to purchase an expensive HDMI cable. Can I get a refund if this is the case?

Hope someone can help.

Many thanks,

Rich