Summary
When you install a Web Access 8 or WebLink 8 .MSP file, the update process checks the Windows Registry for the installation location and updates the relevant files in that specific path.
If you customize your Web Access or WebLink installation by manually creating additional copies of the installation folder and creating additional virtual directories in IIS, the .MSP file will not automatically update those copies.
More Information
After applying the update to the primary installation, you must manually copy over any updated files to the appropriate folders that are in use by your custom virtual directories.