I BUY HALO 3 BUT I CAN'T INSTALL IT ON MY PC

Hello fellow gamer,

After checking what your error code, I believe you have bought a
DLC (Downloadable Content), not the full game content. To access
DLC, you need to have the full game content installed.

For more information regarding this issue, I suggest you read:

https://support.xbox.com/en-GB/help/errors/error-code-0x80073D12

If you have paid money for this DLC which was mistaken as the full game content, I suggest you visit this website as it is where you can submit a refund request:

https://support.xbox.com/en-US/help/subscriptions-billing/buy-games-apps/refund-orders

If you believe you have bought the full game content, this may be a bug, please visit the following website to report this bug:

https://support.xbox.com/en-US/help/account-profile/manage-account/xbox-insider-hub-report-a-problem

Have a nice day and I hope this helps!

Not me, don't have enough space on my harddrive to fit any games on it. Also Bungie said it hinders the performance of the game. Can't remember if it is better to install the Halo 3 multiplayer disk though. I know Halo 3: ODST it is better to install
on harddrive.

Just tried to buy Halo Spartan Assault for Xbox One off of my desktop and it didn't work. So I can't buy anything through my account on my 360, One, or PC. WTF Microsoft.

The Xbox One/website have never been updated to work with your Microsoft account balance to purchase 360 content. The only way to use your balance would be to make the purchase from a 360 console.

Oh thanks for the reply Smwutches, you are my Hero. Only one question: Then I bought Halo 3 on a 360 xbox, can I play Halo 3 on my Xbox one?

Yes. Since it's backwards compatible it would work on the One.