If your Sony VAIO fails to boot to the operating system after start-up, you can access the recovery console from the recovery partition on your hard drive. The recovery console includes all of the repair and diagnostic tools included on the Windows Vista and 7 DVDs, including Startup Repair, System Restore and Windows Complete PC Restore.
Power off or restart the computer. Hold down "F8" when the "VAIO" logo appears onscreen.
Use the arrow keys to scroll to "Repair Your Computer." Press "Enter."
Click "Next" on the "System Recovery Options" screen. Left-click the down arrow to see the list of accounts. Select an account with administrative privileges.
Type the account password into the appropriate field. Click "OK" to proceed."
Choose "Startup Repair," "System Restore" or "Windows Complete PC Restore" to recover your system.