There is a known bug when trying to build 64-bit MSI files. That is, the wrong InstallUtilLib.dll is embedded in the MSI. A workaround to that problem is to use Orca to manually manipulate the MSI file in embed the correct version - the workaround is documented here. However, what if you want to automate this process on your build server? Orca is a windows appication requiring user input. To automate this from the command line, you can leverage a few lines of VBScript code that essentially duplicates ......