Here is the readme for flight simulator 5 patch...

For those of you having problems with sound or joystick, or have a low
frame rate due to the joystick...

I have uploaded a file called FS5PATCH.ZIP to ftp.iup.edu.  This should
fix most problems that users are having.

Please note that FS5 requires EMS memory;  Using EMS memory will speed
up FS5 by 2 to 10 times over XMS only.  If you are having problems configuring
your machine for EMS memory, please read the inside-back cover of your
Pilot's Handbook.

Mark Randel
B.A.O.