Okay. I've been struggling with this for a long time. I've decided to finally ask it out here and see if I can make it work. I have code that I can successfully build on a couple of different compilers (Borland and Pelles) as a DLL and use it from a program written in Visual Basic. We are using the __stdcall for the DLL. I can also compile and produce a DLL using Visual Studio. However, the DLL produced by Visual Studio cannot be called from Visual Basic. We call it but nothing happens. We do not know why. The exports all look good, etc. None of the code is different. So, I have to assume that it is a setting or something. But, we cannot find it. Ideas? Is there an issue with Visual Studio produced DLLs and Visual Basic? Are there workarounds?