FNP_ACT_Installer.dll error when installing

When attempting to install your Revit 2010 product, you might receive the following error and the installation rolls back:

1: 5 2 Failed to Load FNP_ACT_Installer.dll. 3: 126

This error is caused by a conflict in a Macrovision DLL file on the machine, most often seen after installing AutoCAD 2010. To resolve the error you can do the following:

1. Download one of the following zip files, based on the Operating System that you are running:
   
   32 bit Vista/XP: Download FNP_Act_Installer_32_bit
   64 bit Vista/XP: Download FNP_Act_Installer_64_bit
   
   
2. Extract the DLL file to C:\Program Files\Common Files\Autodesk Shared\AdLM\R1, overwriting any existing version.

After replacing the DLL you should be able to install.