okay, i have this process by 95%. I followed the tutorials, got the required files, got the bootdisk, put the xbox HD under slave and everything. When i boot with floppy. I type in 'hdunlock', choose HD, and enter password, and it says done. I do the same process for 'hddisable' but this time it says 'drive not ready'. I posted this problem on xbox-scene board, and no one seemed to know. And i know from previous posts that there are some pretty experienced people on this board, so i hope i'll get treated better here than at xboxscene.
You could always just put your hdd back in your xbox and use carpet magic to unlock it because it does it all for you, just press 1 button and its unlocked.
Then take it out and put it in your pc and it will work fine. Hope this helps.