I too had trouble getting Might & Magic to work past the title page,
so I took a look at the code.  After the 2nd stage DOS boot loader
finishes, control is transferred to the routine at $9000 which continues
loading the game.  However, at $B73B, right before the JMP to $9000, the
expected volume number in the RWTS parmlist is set to $FF.  This causes the
sector reads to fail and the code to sit in an infinite loop.  To fix
the problem, make the following sector mod to side A of the game.

   T00,S01,B3E: 8E EB B7 -> EA EA EA

Now the boot should contine and the game should work normally.  Although
after pressing ESC (twice) to start the game, a text screen of garbage is
displayed (bug?).  Just hit ESC again and the prompt for disk B will
appear.

-lotek