Board Thread:Off Topic/@comment-12005676-20130721001701/@comment-208.100.40.42-20130729170406

The message you posted sounds like the one you get when you're trying to uninstall something. That sometimes happens if you click the setup file for something that's already installed.

In Morrowind the file to open the construction set is TESconstructionset.exe, should be in your morrowind directory.