My laptop died and I have just installed Music Creator 6 on my new computer, a  Gateway SX2110 mini-tower with Windows 8. Now with my new installation, if I open a MIDI file and play it, it hesitates and skips before 20 or so measures are played.
 
It does it with different MIDI files, and in seemingly random places in the piece.
 
I am in ASIO4ALL driver mode.
 
I didn't have this problem with what was installed on my old computer.
 
What happened?

Try doubling the buffer size at "MIDI buffers, prepare using xxx ms buffers". That might help.

first step ^^^^^ increase the buffers.
 
second step, look at the soundcard and determine if the driver is the right one.... or possibly upgrading the card/ interface.