Make your pendrive bootable using cmd

STEPS:

1. Insert your USB into your computer. When your computer finally recognizes

    it, open the command prompt(Run as Administrator).

2. Once inside the command prompt, type: diskpart , then press Enter.

 After that, You will something like this one:

3. Now, type: list disk , All active drives will be displayed to the command

 o    After that, you will want to select your USB. Typically, it's always the   smallest one in size, so you will always be able to tell which one your USB. Now, type: select disk 1

o    After that, Clean your USB. Be sure to back up all data stored on the USB you are using, because you will lose all your data in this step. Type: clean

4. Now, you will create a partition for the USB. Type: create partition primary

5. Type: select partition 1 . This will select the partition you have just created.

o    Now, type: active . This will make the partition active on the USB.

6.  Now, Type: format fs=ntfs . This command will format your USB in NTFS file
     system. This could take awhile time depending on the size of the drive and
     the processing power of your computer. It could take time from a few
     seconds to 15 minutes.

o    Once completed, type: assign .

7. Congratulations, now you have a bootable USB. Type: exit

8. Now, Insert your Windows DVD or mount ISO image in the optical drive and
    note down the drive letter of the optical drive and USB media. Here I'm using
    "H" as my optical (DVD) drive letter and "J" as my USB drive letter.

o    Go back to command prompt and type following commands: H: and hit enter. Where "H" is your DVD drive letter.

o    Now, type: cd boot and hit enter.

o    After that type BOOTSECT.EXE/NT60 J: and hit enter. (Where "J" is your USB drive letter.

9. Once you have done that, Open the DVD from windows explorer
   (My Computer). You might have to right-click on it, then click on "Open".

10. That's all. Now, you have a bootable Pendrive with any OS (Operating Systems).