It depends if you have modded the box...and Fujitsu aren't much use in an xbox..you can't lock 'em so no m$ software
Yes pretty much any.. I prefer Maxtor to Seagate, they seem to run a bit cooler, but you know the drive locking issue... I think I saw a drive compability list somewhere like x-free86, but the specs on the makers website should tell you everything you need to know..They usually say if it can be locked...Apart from that any IDE/EIDE 7200rpm 3.5" drive will do, don't be tempted to get one too big 500GB is about the max or it takes for ever to load up... Where I am a very popular one is the Seagate ST3300831A Barracuda 7200.8 300GB with the 3.06 firmware Not too pricey £103.95..inc tax Please note..the procedure for making a new drive for a softmod is a bit complicated..Unless you have a chip do some serious research first before you pay out lots for a big drive
http://xboxdrives.x-pec.com/?p=list there is the compatibility chart. If you have a chip i suggest you get an Auto Installer disc like Slayer 2.6 or AID 3.0 while you at it. That is the easiest way to format the drive and put a lot of the stuff (apps,dhashboards,emulators & roms, and so on) back onto the new HDD once in. Here is how to install it and format using Slayer 2.6 http://www.teammodders.com/viewtopic.php?t=672
