Creating a bootable windows 7/vista USB disk from DVD

1. first format the pen drive in which you want to create bootable usb drive
2. open command prompt in "run as administrator" mode
3. type "diskpart" in command prompt and press enter
4. type "list volume" and locate the usb drive that you want to make bootable
5. type "select volume <number of the volume>" for example if the volume no is 5 then type "select volume 5"
6. to make this volume active type "active"
7. now exit from diskpart using "exit" command
8. Now we need to create Boot sector on USB drive. We'll use "bootsect.exe" utility for this task. You can find this utility in Windows setup disk. It'll be present in "Boot" directory.
9. go to the boot folder in the setup disk. like "d:\boot"
10. type "bootsect /nt60 g:" here the g: is the drive letter of the usb drive. Replace it with the correct drive letter if your system has some other letter for USB drive.
11. At last, copy all files/folders from Vista Setup DVD to your USB drive and you are done.