I had a Seagate ST340014A (think it's the slim version) out of a faulty XBox and wanted to unlock it so I could use it in a PC. Been spending weeks trying to get into that thing, without avail. I was just about to throw the drive away, until I found this page with simple advice, and lo and behold, it worked. In my case, the first method functioned perfectly with the first password
Seagate+25 spaces.
SeagateUnlockAs I write this I'm coping Windows install files to the drive, so I wanted to share this with others who might be just as frustrated as I was.
UPDATE: I cached this message until I actually got to my fully-installed desktop. It DOES work, and to all those countless websites where I read that a drive can't be unlocked without being installed in the original Xbox, you have no idea what your missing!