Issue with DQE installation / service

We are currently on EP 6 SP13 and have gone through an install. We are experiencing an issue with getting the DQE service to work and are not sure it was installed. In the Portal under 'System Admin'->Distributed Query Engine, it gives a message 'DQE not installed'. Also, in the J2EE Admin Tool / Visual Administrator (go.bat), under the J2E->Server->Services, the DQE service is unable to start.

Has anyone experienced the above issue? If so, how did you remedy this? Can one do a specific 're-install' of the DQE? We need to get this going so we can utilize the JDBC driver connecting an RDBMS to the Portal...

Thanks in advance for any advice on the above.