I copied the OCA file with it as well...but nothing works. as I mention, this is odd since the winform version works fine, but the service one doesn't.

The exception was thrown was System.InteropService.COMException, the error message was : class is not licensed for use. Other than that, it doesn't have any other error. Please note that it works fine on the machine that has both .NET Studio and VB6 installed...but not others. Jimmy

I wrote a service that use VB6 MSCOMM32.OCX for serial communication. I works perfectly on my development machine which has both .NET studio and VB6 installed. But when I bring it over to a computer w/o VB6 installed it doesn't work (i registered MSCOMM32.OCX). I got the following error: System.InteropService.COMException from the service. The odd thing is that the service monitor tool which is a winform application, which also use MSCOMM32.OCX but has a wrapper class that generated by winform, works perfectly as well. the Error when I debug it says: Class is not licensed to use Please help. Thanks