I have got MM9 working well now in windows 7. the only issue is the screen hanging at the little ship when loading a saved game or a new area, but ALT-TAB to the desktop screen and back cures it. I can live with that providing you are not attacked the moment you enter an area!
The settings i am using are:
On the properties of the lithtech program the compatibility mode is set to Win XP (Service pack 2)... other modes may also work.
All other settings on the properties form are un-ticked.
The video options in the program are ALL turned off and I am using the primary display driver in the display adapter box to handle the graphics rather than my G-Force graphics card (although this might actually in effect be the same thing.
ALL other settings are unticked (e.g. blood spats etc.)
The game is totally playable and i have just completed beet hoven and retrieved the manuscript.