You will have to make the pc boot from disc
Turn on or restart your computer and watch for a message on the start up screen about a particular key, usually Del or F2, you'll need to press to this key to enter the boot setup. Press this key as soon as you see the message.
A new screen will appear with options as to which device you wish the pc to boot from.
Then set the optical drive (cd/dvd) player as the boot device, restart the pc with the disc in the drive, the pc will then boot from dvd/cd and you should be able to run the fix.
Try that