I need to install MMM2014 onto an internal drive that is NOT the C boot drive. My C drive is a pair of ssd drives, set up as a raid system, that contains the operating system (windows 8.1) but is only 212 GB in size. Therefore the drive will fill up quickly and I don't want other sofrware on it. I have 2 interbal 3 TB drives I use for all other software.
Run the installer and during the initial screens you will be given the option to do a custom installation or change the install location - you can then specify where the software is installed.