Booting MRI from USB using syslinux - Tutorial
Thought this might be helpful to anyone who wants to use MRI from their USB Pen Drive so this is how I did it and got it fully working 
This is an updated version of the above and will boot MRI fully giving access to all the tools I think although I haven't had time to fully test everything so if you find something that's not working let me know.
Revised 25-01-10
Pre-requisites
MRI
USB Format tool available here - http://www.mediafire.com/?jfokgyfyz4g
Grub4dos-0.4.4 available here - http://sourceforge.net/projects/grub4dos/files/GRUB4DOS/grub4dos-0.4.4.zip/
Syslinux-3.84 available here - http://www.kernel.org/pub/linux/utils/boot/syslinux/
1. Unzip the USB Format Tool and run (its stand alone this time and needs no install). Select your USB Pen Drive and format to fat32.
2. Unzip both Grub4dos and Syslinux to seperate folders.
3. Open a command prompt and navigate to your syslinux folder>win32 and type syslinux X: (where X is the drive letter of your USB Pen Drive)
4. Using the search function copy the following files from your syslinux folder to the ROOT of your USB Drive -
chain.c32
menu.c32
reboot.c32
vesamenu.c32
5. Now go to your Grub4dos folder and copy the following files, again to the root of your USB Drive -
default
grub.exe
6. You now need to create a folder called 'iso' on the root of your USB.
7. Next create a text file on the root of your USB and name it 'syslinux.cfg' then open in notepad and copy/paste the following -
default vesamenu.c32
prompt 0
menu title Geek Squad MRI 5.1.1.0-SX-Cracked
#MENU SEPARATOR
menu background background.png
#
menu color hotsel 30;47 #40000000 #20ffffff
menu color sel 30;47 #40000000 #20ffffff
menu color scrollbar 30;47 #40000000 #20ffffff
menu color help 37;40 #c0ffffff #00000000 std
MENU WIDTH 72
MENU MARGIN 5
#MENU PASSWORDMARGIN 3
MENU ROWS 15
MENU TABMSGROW -10
MENU CMDLINEROW 23
MENU ENDROW -1
#MENU PASSWORDROW 11
MENU TIMEOUTROW -8
#
LABEL -
MENU LABEL Utility Boot Disks
MENU DISABLE
#
LABEL -
MENU LABEL MRI Menu
MENU INDENT 1
LINUX /grub.exe
APPEND --config-file="find --set-root /menu.lst;configfile /menu.lst"
#
label Boot Geek Squad - MRI PE
MENU LABEL Geek Squad - MRI PE
MENU INDENT 1
COM32 /chain.c32
APPEND boot ntldr=/bootmgr
#
LABEL hirens boot disk v10.1
MENU LABEL Hiren's Utilities v10.1
MENU INDENT 1
KERNEL /HBCD/memdisk
APPEND initrd=/HBCD/boot.gz
#
MENU SEPARATOR
#
LABEL -
MENU LABEL System Boot Options
MENU DISABLE
#
#boot from first hard drive
label 0
menu label Boot from ^HD
MENU INDENT 1
localboot 0x80
timeout 100
#
#reboot
label Reboot
menu label ^Reboot
MENU INDENT 1
KERNEL Reboot.c32
#
8. Again create a text file on the root of your USB and name it 'menu.lst', open in notepad and copy/paste the following -
foreground = FFFF80
background = FF0000
timeout 0
default /default
title Launch MRI (5.1.1.0)
map (fd0)/iso/mri.iso (hd32)
map --hook
chainloader (hd32)
boot
title Reboot
reboot
title Shutdown computer
halt
09. Now open your MRI.iso and extract the following files and folders to the root of your USB -
boot - folder and content
SOURCES - folder and content
BOOTMGR - file
MRI.EXE - file
(This is necessary for us to have a working MRIPE that we can boot from syslinux since there is a bug with it running from a mounted ISO unfortunately although I am looking for a solution to this issue because I'd like to include Active Boot Disk or another BOOTMGR loading PE on the USB with MRI)
10. Nearly finished Now rename your MRI iso to 'mri.iso' and copy it to your 'iso' folder on your USB drive.
11. If you wish you can also copy the 'HBCD' folder from Hirens Boot CD to the root of your USB and have use of this also.
12. Reboot your system and make sure your bios is set to boot from USB and see if it works
Same as before if you want to add your own background just open your picture and resize to 640X480, save as 'background.png' and copy to the root of your USB.
If you like you can download the following directly to save some time -
syslinux.cfg here - Updated http://www.mediafire.com/?qmznwmjezkn
menu.lst here - http://www.mediafire.com/?wf4mgnwmfm4
My personal background here - http://www.mediafire.com/imageview.php?quickkey=iymncfmymyy
And if you want all the base files set out so all you'll need to do is copy then to the root of your USB (you will still have to add your own 'mri.iso' to the 'iso' folder and the files from Hirens to the 'HBCD' folder)
Get them here - Updated http://www.mediafire.com/?wdwwlotxygl
That's it reboot your system and make sure USB boot is selected in your bios (obvious but often overlooked especially by me lol) and test to see if it works
Best thing about this method is being able to add stuff, I'm using this as part of my multi-boot USB and ISO project that I'm currently working on. If anyone is interested hearing how I get on just comment here and I'll keep you posted
And a special thanks to Tecchie (see post below) for suggesting I revise the first part of this thread as well as posting my updates, patches and fixes in the thread for those who are building this project as I am or who need additional help with it
Ph4nt0m