If you start a fresh instance of CVI, open a sample project, create a new distribution, then try to build it, do you still get an error? If so, at what point do you get the error? Is it a distribution build error, or do you get the error while bringing up the Edit Installer dialog? Can you confirm that the directory C:\Program Files\National Instruments\Shared\MDF\Bin directory exists, and that it contains a bunch of files including MdfCommon.dll?
When did you begin having this problem? Have you ever been able to build distributions on this system?
Mert A.
National Instruments