USB - Windows 8.1 Create USB bootable

To create and USB Device bootable for Windows 8.1 (or other S.O.) you need:

1. Download Windows 7 USB/DVD
http://www.microsoftstore.com/store/msusa/html/pbPage.Help_Win7_usbdvd_dwnTool

2. Install the program and choose the iso file to put on USB external Key

3. Start PC with USB live

4. Choose Language to install and then:

5. Then choose "Repair your computer", NOT "Install now".

6. select "Troubleshoot" and then "Advanced options". 

7. You'll find solve boot problem

8. Then you could use this command prompt option:

-bootrec /fixmbr
-bootrec /fixboot