@uv

Select a 4GB+ USB Drive.

1. Formatting the Drive using command prompt. Open the command prompt as Administrator. and run the following commands.

        diskpart
        list disk
        select disk 1    (Replace the number 1 with the number of your disk)
        clean
        create partition primary
        select partition 1
        active
        format fs=NTFS
        assign
        exit

2. Make the Drive Bootable

    Insert your windows 7 dvd into the drive or open the image using virtual drive and note down the drive letter. Change the cmd directory to dvd and execute the following commands. Replace D with your dvd drive letter.

        d:
        cd d:\boot
        bootsect.exe /nt60 g:

3. Copy the Installation DVD to the USB Drive.
4. Set your BIOS to Boot from USB and try installing windows7