Several years ago I decided to upgrade my Xbox 360 HDD. I had the original white model that used the side caddy for the drive. Hooked up my replacement drive to the system with the fancy pants transfer cable, initiated the copy feature, and right as it was about to finish it went ape shit and stopped.

There is no copy option on this process, only move. The error ended up not transferring anything to the new drive and deleting everything on the old one. Everything.

I wound up being able to salvage almost all of my game saves with a paid PC program that could restore the file structure from a table of contents wipe. If it wasn't for that program I'd have been screwed.