Error after back up

does any one know what this error is and how to fix it?

an error was detected in the volume shadow copy service(VSS)

the problem occured while trying to contact VSS writers.  Verify

that the event system service and the VSS service are running

and check for associated errors in the event log (0x80042318)

Welcome to the Community.

What is the name of the application displaying this error message and how was it configured with your WD hard drive?