There are two files on your computer that will need to be changed,
AUTOEXEC.BAT and
CONFIG.SYS. You will need a plain DOS text editor to make the changes, one that does not create special characters in a text file. If you look at
this it will give you the basic idea of what you need to do. However I am pretty certain that Acer will not be able to supply you with the DOS drivers you need as Windows 3.1 is so old.