(MM7 had the same problem, but was fixed by reinstall. I haven't actually tried playing yet, but at least it's not crashing on startup.)

Running Win8.1. Used to run on Win8, then started crashing on startup, now crashes on startup even though I've reinstalled. I suspect some security update is at fault (it was for Civ3, problem fixed), but don't know how to even begin trying to figure this out. The error message is that MM6 has trouble loading files & to please reinstall to fix (except that reinstalling has already failed). MM8 merely "stops working." Please help.

P.S.: Tried running Greyface patch 2.0 for MM6, but it won't run ... Win8.1 just asks me what I want to use to run it, and keeps looping back around. Or, if I say with MM6, asks me to insert Disc 2 into the drive (when I'm not running on the discs, obviously).

Did you try the compatibility modes?

Opening cinemtaics are unskippable the first time you watch it. At least that's how it worked.

I just tested ... seems it's every time.

So it looks like something prohibits it from writing to registry or something. Is MM6 white-listed for your antivirus? Do you run MM6 as admin?

or try editing it in registry manually:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\New World Computing\Might and Magic Day of the Destroyer\1.0

Locate the key "Ran Once" and change its value to 1.

OK, tried again ... for some reason, compatibility mode for Win95 actually works now, even though it didn't before. Strange....