Boot Windows PE with command prompt from USB.
You want to boot up Windows PE (preinstall environment) with a command prompt. And you want to boot this from a USB memory stick! Why? It is good for simple editing and/or accessing system protected files. The tricky part is of course to make all this work.
Well, here is the solution.
The Windows® (AIK) for Windows® 7 (download)
A windows 7 installation disc
A USB memory stick. 1GB is enough.
Program to mount .iso files (Virtual CloneDrive: download - its free!)
A bunch of custom .bat files (download)
Start by mounting the .iso file downloaded from "The Windows® Automated Installation Kit (AIK) for Windows® 7" site. Wait for the autostart or start the installation manually with "StartCD.exe" located on the disc.
Start the "Windows AIK" setup. Make sure not to change the installation directory. It should install to: "C:\Program Files\Windows AIK".
After the installation is complete you can unpack your .bat files. Run the files in the right order. This creates a .iso file with your "Windows PE".
NOTE! Between the "Run 2.bat" and "Run 3.bat" you can add files to your PE installation. Info is in the .bat files!
When all the .bat files has done it's job you should mount your windows 7 installation disc. Or put it in your dvd drive if it is a real actual disc. Also make sure that your USB device is connected at this point!
Start your command prompt. Start it as administrator!
In the command prompt enter these commands:
diskpart [enter]
list disk [enter]
You should now see a list. Find out which one is your USB device. Mine was number 1.
select disk 1 [enter] (replace 1 with your disc number.)
clean [enter]
create partition primary [enter]
select partition 1 [enter]
active [enter]
format fs=ntfs [enter] (This will take some time.)
assign [enter]
exit [enter]
e: [enter] (Replace e: with your drive containing the windows 7 disc.)
cd boot [enter]
bootsect /nt60 i: [enter] (Replace i: with your USB device.)
Exit the command prompt. Mount your "Windows PE" iso that the .bat files created. It is located at "C:\PE\winpe_x86\winpe_x86.iso".
Copy all the files from it to your USB drive. And! You are done... Congratulations.