How to obtain OPC Classic server registration information

In some situations it might be necessary to obtain detailed information about how the OPC Classic server is registered in the system. The information is stored in Windows registry, and this article explains how to export this information for further inspection and analysis.

The procedure below start requires the knowledge of the ProgId (or version independent ProgId) of your OPC Classic server, which we will refer to as ProgId (in italics) in the following text.

1. Start the Registry Editor Windows tool. One way to get to it is to type REGEDIT into the Search box.
2. In the left pane of the Registry Editor window, navigate to and select the following node: Computer -> HKEY_CLASSES_ROOT -> ProgId. For example, for OPC Labs Kit Server, you would navigate to Computer -> HKEY_CLASSES_ROOT -> OPCLabs.KitServer.2.
3. From the menu, select File -> Export command (or right-click on the node and select Export command). Enter a file name and press Save.
4. Under the select node in the Registry Editor window, there should be a CLSID sub-node. Select it.
5. In the right pane of the Registry Editor window, there should be a row with a registry value, the Name would be "(Default)" and the Type "REG_SZ". Under the Data column, there will be the CLSID of the server. Write it down; we will refer to it in the following text as CLSID (in italics). For example, for OPC Labs Kit Server, the CLSID value would be "{C8A12F17-1E03-401E-B53D-6C654DD576DA}".
6. In the left pane of the Registry Editor window, navigate to and select the following node: Computer -> HKEY_CLASSES_ROOT -> WOW6432Node -> CLSID -> CLSID (note that this the specific CLSID sub-node under "constant" CLSID node). For example, for OPC Labs Kit Server, you would navigate to Computer -> HKEY_CLASSES_ROOT -> WOW6432Node -> CLSID -> {C8A12F17-1E03-401E-B53D-6C654DD576DA}. Notice (and do not skip) the "WOW6432Node" in the registry key path - it is important to obtain the proper 32-bit part of the registry.
7. From the menu, select File -> Export command (or right-click on the node and select Export command). Enter a file name and press Save.

Note: This procedure is for 32-bit OPC servers running on 64-bit Windows systems, which is how the majority of systems currently in use are set up. The procedure for 32-bit systems is slightly different. On 64-bit Windows system, there are portions of the registry that are for 64-bit and 32-bit subsystems. Also, the view of the registry that you get depends on whether you run the 64-bit or 32-bit version of the REGEDIT program - the procedure assumes that you are running the 64-bit REGEDIT. In some cases, there may be a need to dig deeper, and inspect the 32-bit and 64-bit parts separately.