Install xp / Vista using pen drive--{Simple }

Requirements to create bootable Windows USB:
Windows 7 or Vista ISO or x p.
Pen drive with 4GB+ (2 GB is sufficient for XP).
15 Minutes of free time
Procedure:
Insert your USB flash/pen drive to your system and backup all the data from the USB as your USB drive will be formatted during the process.
Now download WinToFlash tool from here.
Run the tool, and browse to your Windows 7, Vista, or XP