Wow sunny you're way off.
To hotswap you want to either use xboxhdm or xplorer 360 so it can reconize the fatx file system the xbox uses.
First you want to open up your xbox and disconnect the ide cable from the dvd drive. Disconnecting the dvd drive will cause the xbox to throw error 12. Over the years we found out by doing this it will keep the xbox unlocked so you won't have any problems with the xbox attempting to relock itself and screw up your drive.
Now you want to get your computer ready. Turn on the computer and quickly press the pause/break key. If you are using xboxhdm you need to have your xbox drive as the primary master and your dvd drive on the secondary ide cable. As long as the cd will boot and your xbox drive is primary master everything will work as intended. If you are using xplorer 360 you want to connect your xbox hard drive as the primary slave. As long as the computer will boot your os you can connect your xbox hard drive where ever you want, the primary slave is just the most logical.
Remember to let the xbox power the hard drive and only connect the ide cable from your computer to your xbox hard drive. You don't want to power off the xbox while the ide cable isn't connected or your drive will remain unlocked.
Follow the instructions for either tutorial, i'm just trying to refresh your mind. The only reason you're hotswapping is because the xbox uses a eeprom to calculate a code to lock the hard drive. Locking the hard drive is a security measure microsoft used on the original xbox to deter modders/hackers. If you tried to access a locked drive on a computer you wouldn't be able to do anything unless you had a dump of the eeprom or dump of the calculated password.
Anyway here's a couple links to help you
Hotswap with xboxhdm
http://forums.afterdawn.com/thread_view.cfm/548462
Hotswap basics (older tutorial)
http://forums.afterdawn.com/t.cfm/f-117/hotswap_can_fix_xbox_with_error_13_14_16_20_and_21_can_reinstate_xbox_s_hdd_to_factory_condition_can_also_install_reinstall_softmod_files_all_dashboard_problems_go_here_trick_to_use_xboxhdm_in_hotswap-332766/
If you have any questions at all feel free to contact me via my yahoo answers profile.
Good luck