1. Is it turned on? (I know! It does happen!)
3. Are all the cords secured and properly attached and in the correct ports? Example: When connecting your speakers to the computer, the green cord should go into the port indicated for headphones. Or the VGA cord could be attached to the wrong port.
4. Does the computer look "frozen" ? Sometimes a simple reboot does wonders for the device.Go to the Start Menu ans select Shutdown. If that fails, you may have to force a manually shutdown by holding down the power button for 5 seconds. Wait 10 seconds and try turning it back on.
If you have answered yes to all these questions and still have difficulties, seek advice from someone trustworthy to have a look. In the meantime, go "Old School" and plan B. Trust me always have a plan B!