2. Go to Start -> Run, type cmd hit enter. That should bring in the command prompt. (I hope you are running as an adminstrator)
The number of your USB drive will listed. You’ll need this for the next step. I’ll assume that the USB flash drive is disk 3.
4. Now type and execute these steps one by one
select disk 3
create partition primary
select partition 3
That will just to make your disk formatted and ready with partitions.
5. Insert your Windows Vista / 7 DVD into your drive.
6. Change directory to the DVD’s boot directory where bootsect lives:
7. Use bootsect to set the USB as a bootable NTFS drive prepared for a Vista/7 image. I’m assuming that your USB flash drive has been labeled disk G:\ by the computer. So,
bootsect /nt60 g:
You can now close the command prompt window.
8. Now you need to copy the installation DVD to your USB drive. The best way to do it is to use Windows Explorer and that will copy all the files to your USB drive.
9. Now you need to restart your machine with USB primary boot.