It sounds like you forgot to download MATLAB when you downloaded the installer, or your download of MATLAB was incomplete or corrupted, or you're trying to install an add-on toolbox to a directory that does not contain an installation of MATLAB. For the first two cases, try downloading it again and then follow the standard installation procedure. If you're trying to install an add-on toolbox, when the installer asks you where to install, specify the root directory of your MATLAB installation.
If none of those resolve the problem, please contact Technical Support and they can work with you to get our products installed.
