So the demo apps provided with QuickOPC are for OPC-DA, not OPC-A&E. I do have the QuickOPC Kit DA server as well as another DA server (IntelliMAX.OPC.DAServer.1). The following are my findings:

1. I can read the values from QuickOPC Kit DA Server using the EasyOPC.NET Demo Application remotely by clicking on the `Read item` button.
2. I cannot read values from IntelliMAX.OPC.DAServer.1 using the EasyOPC.NET Demo Application remotely by clicking on the `Read item` button. The Exception box shows: `Exception from HRESULT: 0x80040200`
3. I cannot subscribe to the QuickOPC Kit DA Server items from the demo application by clicking on the `Subscribe Item` button, the Exception box shows `Access is denied`.
4. I cannot subscribe to the IntelliMAX.OPC.DAServer.1 items from the demo application by clicking on the `Subscribe Item` button, the Exception box shows nothing but there is no changing value in the Value box.

And like I specified before, I've also tried Visual OPCTest Tracer DEMO to subscribe to both i.e. QuickOPC Kit Event Server and another server I'm running (IntelliMAX.OPC.AlarmServer.1). The demo application seems to easily subscribe and fetch the alarms from both IntelliMAX.OPC.AlarmServer.1 and QuickOPC Kit Event Server:





I should also specify that it's only the remote subscription that's problematic. Subscription to servers running on the same machine works fine.

I have two kinds of applications:

1. A console application, I run it through a Command Prompt initiated in Administrator mode.
2. A Windows Service which runs under the "LocalSystem" account.

The firewall is disabled on both the source and the target machines.
The behavior for both of these is same.

Hi, I tried this too, replaced the ProgId with CLSID, still the same error:

System.UnauthorizedAccessException: Access is denied

Thankyou for the reply. I've tried all of the configuration combinations above but the problem remains. Every subscription to the OPCLabs KitEventServer results in System.UnauthorizedAccessException: Access is denied.