I made the mistake of trying to install this verion without uninstalling the previous version. The install crashed part way though. I exited the installer and tried to un install the old version but the uninstaller was no longer there. I am guessing that the new installed tried to do an uninstall and failed. I therefore deleted the contents of the MPE folder in C:/Program Filers and resinstalled - this time it went ok.
TIP - Uninstall the previous version before installing the new one.