1-Click Start, type cmd.
2-At command prompt, right click and select “Run as Administrator” type the following command , and then press ENTER:
3-Type the following command a command prompt, and then press ENTER:
4-Troubleshoot the devices and drivers in Device Manager.
NOTE: Click Show hidden devices on the View menu in Device Manager before you can see devices that are not connected to the computer.
5-When you finish troubleshooting, close Device Manager.