This guide is for users wishing to obtain and assemble the necessary hardware for use with the Mega X-Key software (www.xbox-saves.com).

Although no assembly is required here, it is imperative that you obtain a
32MB USB flash memory drive that is fully compatible with the Xbox and with the
Mega X-Key software.
Not all brands of 32MB USB flash drives are the same, just like not all 40GB
hard drives are the same. They may vary in the number of cylinders, sectors,
etc. that they report and may also vary in total number of bytes. Some may
calculate each megabyte based on each kilobyte being 1024 bytes and some based
on each kilobyte being 1000 bytes. Some might actually be 31MB, some 30.5MB,
etc., etc.
The Xbox formats memory cards as FATX and divides it up into a bunch of 16K
“blocks”. So, the total actual capacity of the USB flash memory drive should
be evenly divisible by 16,384. If not, the drive will still appear to work but
may yield strange results as you get closer to the end of the drive and may be
unreliable.
On the PC, there is obviously no built-in support for the FATX file system in
Windows, so it has been built into the Mega X-Key software. To do this, Mega
X-Key uses low-level access to read and write to the drive. As such, it is
imperative that the USB flash memory drive report all it’s information
accurately, such as cylinders, sectors, etc. Most, but not all brands do.
We will continue to test different brands of USB flash memory drives and post the results of which do and do not work with Xbox and Mega X-Key software at www.xbox-saves.com. But for starters, we know that the FMI (Fujitsu) brand of 32MB USB flash memory drive, available at most CompUSA stores, works great, while the “Universal Smart Drive” model by K&C Technologies does not.
Don’t forget, you always have the option of purchasing the Mega X-Key retail package from www.xbox-saves.com which includes the pre-assembled cable, “official” 32MB Mega X-Key USB flash memory drive, and software for a price that is very competitive with, if not cheaper than, what it would cost to build yourself.