How To Make Usb Bootable For Windows7 and Windows8

Making a usb bootable is very easy and it helps alot if you have a notebook or laptop without cd rom or any pc whose cd rom is not working so you can install win7 and win8 by usb on that machine.
I will show you how to do this in the following steps and for you I am also providing the             snapshots of every line of code I am writing to make usb bootable.
1.  First connect your usb to the machine having CD Rom fully functional.
2.  Go To ::: Start>>Search>>cmd>>Press Enter.
3.  Write diskpart in the command prompt.It will ask you to use command prompt as an   administrator.So click on yes.A new window will appear.Now you are using command prompt as an administrator.

4.Enter "list disk" in the command prompt.A list will appear also showing your usb drive and other drives like Drive C, Drive D.

5.  Now to select the usb drive,usually the drive having the lowest space is the usb drive so you can easily select the usb drive(in my case usb drive is Disk2),write "select disk2".

6.  Now you have to clean your usb drive.Be carefull to backup all your usb data because you will lose all your data in this step.Write "clean".

7.  Now it is the time to make partition in the usb.Write "create partition primary".

8.  Now write "select partition 1",this will select the partition you have recently created.

9.  Write "active".This will active the selected partition.

10.  Now it is the time to format the usb.You can format it manually  or through command prompt.Usually the format through command prompt is much longer.
MANUALLY ::: My Computer>>Right Click On The Usb Drive>>Format>>ntfs.
COMMAND PROMPT ::: Write "format fs=ntfs"

It will take time of maximum 45 min so don't panic.
11.  Once your usb is formatted so write "assign".

12.  Congratulations, you now possess a bootable usb.Write "exit" in command prompt.
13.Now it is the time to copy your windows iso file to your usb.Note down the drive letter of usb and the CD/DVD drive.
Here I am using 'D' as my DVD/CD drive and 'H' as my usb drive letter. 
Open command prompt again and write the following the following commands :
D: CD BOOT and press enter.Where 'D' is my CD/DVD drive letter.
CD BOOT and hit enter.
After that write BOOTSECT.EXE/NT60 H: and hit enter. (Where 'H' is my usb drive letter).

14.Once you have done that,open the CD/DVD disk from My Computer. Right Click on 'Open'.Select all that you can see and copy to your usb drive.

Now Install your operating system through usb.
For installing,go into BIOS,which is only accessible when you turns on the computer.You see an option,when the computer boots,that to press the F2 key to enter BIOS.When you are in the BIOS,Go to Boot Options>>Boot Device Priority and make your usb show on the top of the list.This is the way how your computer will load from the usb when it reboots and you will be able to install your operating system.