Happy to say XboxDumper was able to create correct partitions (C & E) on a stock 8gb Seagate hdd under the following test conditions
XP Live (using only 256Mb ram).
The following were noted:
In all tests XboxDumper was unable to write the 'magic' value to at offset 0x600. I used a HxD
to write the required value (I used HxD portable for XP Live)
Installation of XBMC using xplorer360 beta 6
worked fine in all cases.
Much to my disappointment, I was unable to lock/unlock using the Windows hdtool as my bios places a security freeze on the hd (It's a pity the security freeze feature cannot be disabled :-). Still, I was able to run low level commands to view the state of the drive. I did try running hdtool anyway but I encountered the same 'freeze' as reported by tester in post 32
of this thread.
Theoretcially, it should be possible, if your bios allows you to disable the security freeze function, to lock/unlock and rebuild a Xbox HDD using XP live and the tools suggested in post 9
in this thread.