is there a separate dll to launch the dual version?  I have the presents for the dual setup but only the single version loads so maybe i need to look for another dll?

Hi – yes, H910 Dual Harmonizer is a separate dll. It should have installed alongside the H910 Single Harmonizer when you installed the plugins. Make sure that your DAW is set to look at the appropriate VST location (by default: C:Program FilesCommon FilesSteinbergVST2 for 64-bit, C:Program FilesCommon FilesSteinbergVST2 for 32-bit).