Appuyer sur F12 lors du démarrage !!!!

Solution

1. Attach the USB device to your system via any available USB port.
   
   
2. Press and hold the Power Button for few seconds to turn off your system completely.
   
   Note: For Windows 8/8.1/10, you need to restart your system first before proceed following steps.
   
   
3. Power on your system. Press F12 button immediately as Thinkpad logo appears.
   
   
   
4. You should see a menu pop up with a list of choices on it. Select your USB drive using arrow key and press Enter.
   
   
5. Your system should now boot from the USB drive.