STEP 1:-
Go to the site and download the program
http://www.winsetupfromusb.com/files/download-info/winsetupfromusb-1-8-exe/
STEP 2:-
Extract the files and run the appropriate version for your pc, 32 bit or 64 bit.
STEP 3:-
Make sure that the usb is formatted to ntfs and has enough space for the iso files.
You can use the program to get it done.
STEP 4:-
Use the appropriate tab in the program to add windows iso.
Hover the mouse over the tabs to see description for help.
STEP 5:-
Click go and wait for the process to finish.
Add as many operating systems as you want, just keep repeating the process, remember to use the appropriate tab to add your iso files
After you are done you can use the program to test it out
