Open the Command Prompt from the “Start” menu. Type “diskpart” and press “Enter.”
Type “list disk” and press “Enter.” Check the list of attached media to find the number of your flash drive. The storage capacity will be the best clue.
Type “select disk x“, replacing “x” with the number of your flash drive,
“Clean” and press “Enter.”
Â “Create partition primary,” and press “Enter.”
“Select partition 1,” and press “Enter.”
“active,” and press “Enter.”
“Format fs=fat32,” and press “Enter.”
“Assign,” and press “Enter.”
“Exit.”and press “Enter.”
Type the following command: “xcopy d:*.* /s/e/f g:” Replace “d” with the drive letter of your DVD drive and “g” with the drive letter for your USB flash drive. Press “Enter” and wait for the files to copy. When this finishes, your USB flash drive is now bootable.
Restart your computer and, as soon as it turns back on, open the BIOS setup. (This step varies by computer manufacturer. You’ll need to press a key while the initial startup screen is visible. Common keys include “F2” and “Delete.” The key should be listed on the initial screen.)
Find the “Boot” section of the BIOS interface. You’ll see a list of all possible bootable devices attached to the computer, listed in descending order of priority. Thus, your hard drive will probably be listed first, since your computer usually boots from there. Other possible devices may include the DVD drive, the Local Area Network, and your USB flash drive.
Move the USB flash drive to the top of the boot list. Now your computer will always check the USB flash drive before booting from the hard drive. So if you need to re-install your OS and the DVD or CD is missing or damaged, you can plug in your USB flash drive and follow the instructions that appear.