Can't play downloaded game

Don't know why, but IE9 won't post the content.  Here is my original post:

Game or add-on you are having issues with.

Halo:  Combat Evolved

Date you bought the content.

6/4/11

Purchased with points or credit card?

Don't Know

Specific issue you are having.

When I try to launch the game, I get the following error:

"The game couldn't start.  Try downloading the game again"

Any error code or message you are receiving.

Hey mate, do you have an HDD in your console? If so, what size? When was it purchased, and where was it purchased from?

I have a 250GB hard drive in it.  I purchased it from a local store about 1-2 months ago.  I have demo games that I've downloaded that work fine.

What store in particular? Issues can arise if the drive is second hand (and a lot of those imitation drives look almost exactly like the real thing), or if a non first-party cable is used on the drive. The best way to test this would be to try the game on a friend's console who bought their HDD with the console, as well as trying a different Xbox Original game on your console.

Why would the hard drive work for other games, but not for a downloaded Halo game?  How can I get my money back for a game that doesn't work?