MAKE VISTA USB BOOTABLE JUST USING CMD

This is the step by step

1. Insert your USB (4G+preferable) stick to the system and backup all the data from the USB as we are going to format the USB to make it as bootable.

2. Open elevated Command Prompt. to do this, type in CMD in Start menu search field and hit Ctrl+Shift+Enter. Alternatively, navigate to Start>All programs>Accessories>right click on Command Prompt and select run as administrator.

3. When the Command Prompt opens, enter the following command:

DISKPART and hit enter.

LIST DISK and hit enter.

Once you enter the LIST DISK command, it will show the disk number of your USB drive.

4. In this step you need to enter all the below commands one by one and hit enter. As these commands are self explanatory, you can easily guess what these commands do.

SELECT DISK 1 (Replace DISK 1 with your disk number)

CLEAN

CREATE PARTITION PRIMARY

SELECT PARTITION 1

ACTIVE

FORMAT FS=NTFS

(Format process may take few seconds) 

ASSIGN

EXIT

Try it, simple and easy....(Only Work for Windows Vista)