Creating a DLL Driver for Use in VB

Hi,

I am trying to export a dll file for use in VB.  I used the build > dll option within my project to create a dll, but when I try to add the reference to Visual Studio, it says that it is not a valid assembly or COM component and I cannot add it.  Is there a setting I should set in the build settings to ensure this works?

Thanks,

Billy Maier