When you cannot start Windows, follow these steps to restore computer system files.
If you use Recovery Media (optical discs) on the model without a built-in optical disc drive, connect an external optical disc drive (not supplied) to your VAIO computer. See Connecting an External Drive for more information on how to connect the external optical disc drive.
If an AC adapter or a power cable is supplied, plug it into a power source.
Follow the on-screen instructions until the Choose an option screen appears.
The System Restore window appears.
The confirmation window of the selected restore point appears.
Your VAIO computer restarts after system files are restored.