Also, I can confirm that "OPCLabs.EasyDAClient.5.2" is still the proper ProgID with QuickOPC version 5.3. There have been no changes to the COM interfaces in version 5.3, and thus we have decided to keep the ProgID.

First, please obtain the details of the error. Both IIS and Internet Explorer try to hide it; you need to change the "Detailed errors" settings in IIS (the precise steps depend on the IIS version), and, if you are using IE, turn *off* the "Show friendly HTTP error messages" settings. More about this: e.g. stackoverflow.com/questions/2640526/detailed-500-error-message-asp-iis-7-5 .

Second, you may be dealing with the same issue as described here: www.opclabs.com/forum/com-general/1296-help-opc-php-in-iis-7?start=0 , please read it too. Specifically, if, after turning on the full error messages, you get "Class 'COM' not found", then you might be missing

- see

stackoverflow.com/questions/10678325/class-com-not-found

www.php.net/manual/en/com.installation.php

Subject: Trial Version - IIS 500 Error
Note
I downloaded the trial version of your QuickOPC 5.3 product. I did the Full Install option. I am trying to get the PHP example to work but my IIS server keeps giving me an error 500 (Internal Server Error). It works fine for other PHP pages which do not use your product. Any ideas what the reason could be? I am running on a Windows 8.1 machine using the PHP example as is (no changes). I noted that your PHP examples refer to the COM object "OPCLabs.EasyDAClient.5.2" but the QuickOPC version is 5.3. However changing this did not help.