Format a computer with a pen drive

Easy step to format the computer from Pen drive
Step 1: Copy the bootable cd or dvd in your pen drive
Step 2: Now restart your computer and press boot option
Step 3: Select the USB option
If this USB option doesnot work then,
then open My computer
click on your pendrive
double click on setup.exe
then Format option will appear
now You can format your computer with pendrive
                             OR

1. plug ur usb pen drive
2. go to cmd promt run as administrator
3. type the following-
diskpart
list disk
the number of ur usb vol be listed. ( assume usb drive is disk 1 ) ,then type-
select disk 1
clean
create partition primary
select partition 1
active
format fs=NTFS
assign
exit
( now ur usb is bootable )
4. copy the windows vista\windows 7 dvd to ur usb
5. restart ur computer
6. go to bios
7.then go to boot option
8. select boot from usb and press enter
9. thats all enjoy