how much memory does the xbox hard drive have

[DRAGoN.X]

An xbox hard drive has anywhere between 8-10 GB. Half is used as temp storage (like when you run a game it loads stuff from the DVD to the temp drives, X,Y,Z)
Unless your planning on getting a modchip there is no use in upgrading it. That 8-10 GB will service you fine. Also unless you get a modchip you could put in a bigger one now but how do you plan to format it in FATX. You can't use a computer. And unless you have a modchip bios that can boot the LBA 48 hack the xbox won't be able to see beyond 138GB. And all of that falls on if you can even format the drive. Oh and I forgot something else! How do you plan to lock the drive once you get it installed.

So unless you have a modchip, upgrading a harddrive is impossible!

And if you do have a modchip I'll gladly help you (Although I think you should have mentioned that before so I wouldn't have to write all of this.)