Downloaded Xbox originals wont play on my Xbox 360.

[FrostyTop]

Is this a hard drive purchased from ebay?

You do realise that none of them are partitioned properly and will not allow playback of Xbox1 games?

I can actually help you fix this no problem but you will need

1. Xbox HD -> USB\SATA adaptor

OR

2. Laptop with mini sata connection.

 

EDIT - This definately sounds like you've got a homemade 120GB that has't been formatted properly in china\hk.