How to install win 7 from a usb

This is a tutorial about how to install windows 7 from a usb drive.This tut seems to be easy when compared to other posts in internet.I'm writing this in simple language.
ALL YOU NEED IS
1.Thumb drive having 4 GB of capacity.
2. Win 7 dvd



PROCEDURE
Step-1: Plug-in your USB flash drive and backup all the
existing data in it.
Step-2: Open the command prompt. If you are using
Windows 7/Vista then open it with administrator rights*.
* Goto Start -> All Programs -> Accessories -> Right-click on
“Command Prompt” and select “Run as Administrator”.
Step 3: In the command prompt, type in the following
command:
DISKPART
This will start the Microsoft DiskPart utility.
Now issue the following command:
LIST DISK
This will show you a list of  available disks on your system.
Disk 0 is usually the hard disk. In my case, Disk 5 is the USB
drive (this can be a different one in your case). Now issue the
command as shown below:
SELECT DISK 5
NOTE: In the above command, 5 is the USB drive number on
my system. If you have a different number on your system,
then you need to replace 5 with that number.
Step-4: Now issue the following list of commands one by one
as shown below:
CLEAN
CREATE PARTITION PRIMARY
SELECT PARTITION 1
ACTIVE
FORMAT FS=NTFS QUICK
ASSIGN
EXIT
Minimize the command prompt and proceed to the next step.
Step 5: Insert the Windows 7/Vista installation disc and note
down the “drive letter” of your DVD drive. In my case, it is
“H:”. Now type the following list of commands as shown
below:
H: CD BOOT
CD BOOT
BOOTSECT.EXE /NT60 M:(NOTE: M: is your USB drive letter)
EXIT
Step-6: Copy the contents of your Windows 7/
Vista installation disk into the USB flash drive.
That’s it! Your USB stick is now ready to boot and install the
OS for you. Don’t forget to enable the “USB Boot” option and
change the “boot priority to USB device from hard disk” in
your BIOS settings.
THANK YOU