Device Manager is Blank

Symptoms:
No Network Cards on the Network Connections window.
No Sounds.
No Safely Remove icon when plug in usb device.
No Local Area Connection icon displayed on the tray.
and many more.

Solution:
Open Device Manger by...
1. Click Start
2. Click Run...
3. Type services.msc and press enter
4. Scroll down and double click the Plug and Play service
5. Change the Startup type to Automatic
6. Restart your computer

and your computer is now working properly.