First things first, is it an official Xbox hard drive? If not, you might consider getting one that is.
Now, on to the fix(es). There are multiple YouTube videos that deal with this, and everyone seems to have their own fix. There's [http://www.youtube.com/watch?v=UVgr5JyzCrc|this young man] who simply does some cable unplugging and plugging to get the error code to go away. I'm sure a little more digging will bring up a dozen more potential fixes. If you find one that works, come back and let us know.