In settings.txt I changed this portion to create another folder and mount the second partition.
# Mount your USB Pen Drive, so your script and images can be located. Don't mind the errors at the linux promt on imaging.
mount /dev/sdb1 /usbhd
mount /dev/sdb2 /usbhd2
In the PrebootScriptUSB.s I made the following changes.
#Because we reimage existing computers to upgrade to Windows 7
#Because we have all DELL laptops and desktops
### Add-on Image ###
MODEL=`hwinfo --bios | grep Product`
case $MODEL in
echo "Unknown model ($MODEL) aborting..."
#Portion for local imaging
# I use the shortened commands with a dash "-" because they are the only ones that have worked for me consistently when typing or scripting commands. Depending how you install Windows (XP or 7) you may not need the -size=100 or -pc2 commands, those create the System boot partition that Windows 7 uses by default.
#Deletes all existing partitions
#Creates a boot partition of 100MB
img -pc1 -type=ntfs -size=100
#Makes the boot partition active aka bootable
#Creates a Windows partition on the rest of the disk (size is overridden by what's in your image)
img -pc2 -type=ntfs
#Applies all the partitions from a Windows image to the newly created partitions
img -rl /usbhd2/Win7-Base-Clean-MAK.ZMG
#Applies the model specific addon file containing drivers etc.
img -rl /usbhd2/$ADDON
#Applies an unattend.xml addon for sysprep customization.
img -rl /usbhd2/Win7-Addon-SOS-unattend-sr0.xml.ZMG
#Applies an addon that contains the Zenworks Adaptive Agent
img -rl /usbhd2/Win7-Addon-ZenworksAdaptiveAgent-x64.zmg
One thing I've noticed is I feel like this whole Unetbootin process may not be using the Tuxera enhanced NTFS driver, even though I specified to use the tntfs_bootcd.iso for the script and it appears to have put the tntfs.ko in the addin folder. This might require an extra module loaded that doesn't get called, but I haven't had time to dig into it yet.