These instructions are for the computers that are stuck in an automatic repair loop. They can save you time, because you will not need to remove the hard drive from the computer to save user data.
Turn off the computer
Plug in external hard drive
PXE boot the computer
Click the "Exit to Command Prompt" button
Type the following command to confirm that the C: drive contains the user information
dir C:\Users
Verify that the user profiles include the name of the user. If not, try different drive letters
Type the following command to confirm the external hard drive is mounted to the D: drive
dir D:
Verify that the contents listed match what you know is on the external drive. If not, try different drive letters
Type the following command to create a directory on the external drive
mkdir D:\<foldername>
Change <foldername> to whatever you want. I use the name of the computer
Type the following command to backup the user's data
xcopy /E C:\Users D:\<foldername>
This will not copy any hidden folders, still working on figuring that out. It grabs all normal files
Type the following command to restart the imaging process
wscript.exe X:\Deploy\Scripts\LiteTouch.wsf
Remember to select the "Move User Data Option" to copy all of the user data to the new image