As King says, you have to put the real mode driver and all that goes with it (MSCDEX.EXE) in your DOS configuration files. An easy way to do that is to create a Windows Emergency Boot disk, and it writes those for you for CD ROM support. If you have an old Win98 E-disk, then just use that syntax and drivers in your own configuration files (AUTOEXEC.BAT and CONFIG.SYS.)