A viewer named SHANI DESHWAL asked the question
How to boot OS by using PEN-DRIVE?
Well you can, if you have ONE SOFTWARE & the required BOOT FILES,
The boot files for example is WINDOWS 7 ULTIMATE OS files,
step 1: Download the OS file you wanted ( Eg: Win 8,Win 7,etc..,)
step 2: Now download the WIN TO FLASH software here