What dashboard are you on mate.
(I'd also get NAND Flasher 360 for XBOX 360 v1.2.0, when you copy the contents of the folder to a usb stick and put it and launch it on your 360 you'll be greeted with 2 options, read or write nand" of course read you nand, this will put a copy of your nand onto the usb key. You will need this if your wishing to update your dashboard, put it back in your computer and rar the file and then save it some where safe!!!)
Oggy pretty much covered it in post #20 >>>>>>
here <<<<<<<<
Or like me you can do it the old fashioned way.
which means burning xex menu to CD and then putting that in the machine.
Load it up and you'll get to the xex menu, then copy the code9999 folder (by pressing buttons on the controller you'll be greeted with copy, paste, create options") what you doing is your copying the contents of the CD to the xbox so you can boot into xex menu from the HDD rather than the cd)
go to the CD Press copy on the code9999 folder then go back to your HDD, then look for a folder called "msd content" If you go into this folder you either need to create a folder with sixteen zero's in there, if you don't have it (You can create the folder in xex menu or by using an ftp client to log into the xbox and go to the HDD Content folder, then just create a folder with all them zero's, 16 in fact)
Go back to the xbox and then paste the c0de9999 folder
to the 0000000000000000 folder on the HDD drive. (So c0de9999 from CD to HDD
> HDD\ Content \ 0000000000000000)
So on the HDD you'll have some thing like
MS HDD
\ Content \ 0000000000000000 \ c0de9999 \ 00080000 \ C0DE99990F586558
You will then be able to run xex menu from the HDD not using the CD/DVD rom!
Pretty much what Oggy posted again mate in that thread for installing FSD and "installer"
6 minutes 47 odd seconds in this vid you'll see what i mean. (I don't go through the whole process but you'll see what I mean about the copy/paste options etc)
PLEASE CHECK WHAT DASHBOARD YOUR ON 1ST MATE I'D HATE YOU TO GOOSH IT UP!
Oh and I found it a lot easier if you use a hard drive that's formatted to xbox 360 by the xbox and attached to the side of it, like the normal HDD's I had a bit of a mare trying to get FSD to run from the external USB/HDD.