OK, this is more note to myself, but I think you might find it useful as well. I was trying to install Windows 7 on my laptop which does not have DVD drive so I had to do it from flash drive.

You need 4 Gig flash drive for this, which is what I’ve used.

Here are step by step instructions:

1. Insert USB Flash Drive
2. Insert Windows install DVD
3. Run Command prompt
4. Type:

   diskpart

5. Type:

   list disk

6. Note the disk number of your USB Flash Drive from the list that comes out. In my case it was disk 2
7. Type:

   select disk 2

   (note that you need to replace disk 2 with the number of your flash disk)

8. Run following commands (please make sure you have selected right disk since this will format it):

   clean
   create partition primary
   select partition 1
   active
   format fs=fat32
   assign
   exit

9. Now copy content of your Windows DVD disk to Flash Drive. Type:

   xcopy e:*.* /s/e/f g:

   (note that you must replace e: with the drive letter of your DVD drive and g: with drive letter of your USB Flash Drive)

10. That’s it. You can now use your USB Flash Drive to install Windows on new machine.

Hope this helps.