The Plug and Play service enables a computer to detect and configure new hardware devices. If this service is stopped new hardware that is installed will not be detected, configured, or available to the Windows Operating System.
A service can stop for many reasons, including:
The service was stopped by an Administrator.
The service encountered an exception that stopped the service.
The service was improperly configured, which prevented it from starting.
The service was prevented from starting because the user account assigned to the service could not be authenticated.
The service can be restarted using the Services snap-in which can be accessed through the Computer Management console task:
Start Computer Management Console