i have a home music production set up and was using the mpu 401 joystick port as my midi interface

now in my midi preferences of reason i cant see mpu 401 which i used to select b4
and in my device managr i cant see it either, probably some files got deleted from the sys

actually im quite confusd about it
can anybody help me out,
where can i find the necessary drivers?
i have a sis 7012 mobo, win xp and audiotrak maya mkll sound card