Original Xbox

Upgrading the HDD

The Original Xbox locks its hard drive to the console using a key derived from the EEPROM. A larger replacement drive must be re-locked with that key, or the console will reject it. Back up your EEPROM before starting, because without it you cannot lock a new drive.

Upgrading the hard drive gives you far more room for homebrew, media, and legally-owned game backups. A modded console is required, since the stock dashboard will not accept an unlocked or unfamiliar drive.

Back up keys and data

Save your EEPROM and copy any content and configuration you want to keep from the original drive.
Prepare the new drive

Connect a compatible larger drive and partition it the way the Xbox expects, so the dashboard will recognize its layout.
Re-lock with the key

Apply the key from your EEPROM to lock the new drive to this specific console, matching how the original was secured.
Restore and verify

Copy your saved files and dashboard back, then boot to confirm the console accepts the new drive.

Choosing a drive

Pick a drive known to work with the console and within supported capacity limits. Larger is not always better if compatibility suffers, so favor proven models.

The key is everything

The whole process hinges on the EEPROM-derived key. Treat that backup as priceless and you will avoid the most common upgrade pitfall.