MS DOS problems

help im trying to install a game
which is simple for my computer to run
but the problem is when i want to install it
i have more than the capable specs to be able
to install this game apart from i get the following
message when i run through MS DOS
c:\windows\system32\autoexec.nt. the sytem file is not suitable for
running MS-DOS and microsoft windows applications choose close
to terminate the application

can anyone help me with this problem it is proberly really simple but
i have ran out of ideas

cheers