you are going to have to elaborate slightly.
i'm assuming you mean the original Xbox.
I'm assuming you've already softmodded or hard modded it. if not, you are going to have to. a bone stock xbox won't work with an aftermarket drive.
then....
yes the drive is locked.
1ST and foremost...you need to find out if that drive you have there will even WORK with the xbox -
http://xboxdrives.x-pec.com/?p=listyou are going to have to unlock the drive with the xbox then transfer the powered drive to the computer and then read the data from it. not at all what you are able to do since you say you have no IDE ports on your computer. so go find an old computer?
OR
you are going to have to exctract the key and use a program to unlock the drive using this key. when you softmod you usually backup the bios to the harddrive. you can FTP into the xbox and pull the file and extract the key. you can then use the key to unlock the drive and read the data. this is ideal.
OR
you keep the original drive and add an additional drive to the system (you will lose your CD drive) and have your frontend point to the other drive for games and whatnot. not ideal, but it works.