I've got thesame problem. Usually when this occurs the filename extension is incorrect for the platform, the filename doesn't match that of the setup routine, or the subroutine wasn't declared extern. I tried all that, but I didn't get far. In a previous post Miller noted that this could very well be an incompatability problem with MSVC++. i'm currently using version 6, and there are several types of DLL files I could generate. I really don't have a clue what the correct settings are for PD. The external tutorial is now at least 5 years old, I highly recommend upgrading it to present time standards, it doesn't say anything about a major compiler that a lot of people are using.. More help of course is very much appreciated!