How to install Windows 7 from usb

Installing from usb is much more faster than a DVD and new netbooks do not have dvd drives and can use only usb.If you happen to have an orginal windows 7 dvd and cannot install it on your computer as you dont have a dvd drive or if you want to use the usb to install here is the offical way.

Microsoft has released an offical tool which can help netbook users to install windows 7,it can be used on all other computers too.

1. Get a pendrive of space 4gb.
2. backup all your data
3. download the windows 7 usb dvd tool from here
4. install the application
5. run the application
6. browse to windows 7 iso location.if you dont have an iso create from your dvd
7. click next and you can select usb
8. select the desired usb 
9. press start copying
10. use the pendrive for booting after seeing the message that the copying is done.

Note to use a 64bit iso you must install the application in 64bit windows 7
If you have any further doubt then please add it in the comments.