You need a driver in addition to *dex.exe

Often you can use a universal ATAPI driver such as the famous oakcdrom.sys but there are others.

i have install the driver but i don't know how to use this oakcdrom.sys, how can I do?

Add the driver to your config.sys

1DEVICE=<driverfile>.sys /D:CD1
2

Of course replace <driverfile> with the real file name

In autoexec.bat

1MSCDEX.EXE /D:CD1

i don't know this drivefile...maybe is oakcdrom.sys? where i can locate this file?

DEVICE= oakcdrom.sys /D:CD1 (why /D:CD1?)

i have download atapi.zip from this page, ok?

http://driverzone.com/drivers/atapi/

You can name it what ever you want as long as it matches in config.sys and autoexec.bat

So /D:BIGGIANTSTEAMINGPILEOFDOGCRAP
should work just as well as long as it is the same.

That driver would probably work. You could probably run the install program and it might change the config.sys and autoexec by itself

ok, the drivers have a install.exe
I hope he does everything automatically because I don't know which file I have to add in the string config and autoexec...

this is a INSTALL.INF content:

;
; LG Electronics Inc.
; CD-ROM Installation Information
;
;---------------------------------------------------------
; Configuration of system
;---------------------------------------------------------
[CONFIG]
SYS_NAME="GSCDROM.SYS"
DEVICE_NAME="MSCD000"
MSCDEX_LOC=BOTTOM

;---------------------------------------------------------
; MAIN -> Installed directory
; SUB -> Installed sub-directory
; FORMAT <DIRECTORY_NAME>="Title","DIR_NAME",DIR_INDEX
;---------------------------------------------------------
[DIRECTORY]
MAIN="Installed Directory","C:\CDROM",0,0

;---------------------------------------------------------
; DISK_NUM="DISK_NAME","KEY_FILE"
;---------------------------------------------------------
[DISKS]
1="Disk 1","install.inf"

;---------------------------------------------------------
; FILE INFORMATION
; FORMAT <DISK_NUM>=<DIR_ID>,<Group_ID>,<DEST_FILENAME>,
; <SRC_FILENAME>,<ORG_FILESIZE>
;---------------------------------------------------------
[FILES]
1=0,0,GSCDROM.SYS,GSCDROM.SY_,29323
1=0,0,MSCDEX.EXE,MSCDEX.EX_,25361
1=0,0,CLOSE.EXE,CLOSE.EX_,33420
1=0,0,EJECT.EXE,EJECT.EX_,33628
1=0,0,UNLOCK.EXE,UNLOCK.EX_,1231
1=0,0,LOCK.EXE,LOCK.EX_,1227
;
[END]

Make a backup of your config.sys and autoexec.bat and just run it.

Ok, i will try tomorrow

First of all, it might be good to know a bit about CD-ROM in pure DOS.

For CD/DVD access in DOS you need two things: a DRIVER and the REDIRECTOR. The driver is responsible for communicating with the hardware unit itself, and the redirector will redirect a logic drive (D:, E:, ...) to the contents of the disk, whose raw data it gets from the driver. When you load the driver you create a special device "file" that you can give a name to, i.e. CD1 (I personally prefer a name that is less likely to conflict with actual files on the disk, like MSCD001), and when you start the redirector, you need to provide the device name it will communicate to.

First of all, the driver. That you'll need to load from CONFIG.SYS. There is OAKCDROM.SYS that Windows uses on its bootdisk, but it is a conventional memory hog. I suggest, instead, vide-cdd.sys that you can get here. Copy it to C:\WINDOWS and add the following line to CONFIG.SYS

1DEVICE=C:\WINDOWS\VIDE-CDD.SYS /d:MSCD001

Then for the redirector, you can use MSCDEX (which comes with DOS and Win9x) if you do not mind the conventional memory it consumes. Just add this to AUTOEXEC.BAT

1MSCDEX.EXE /d:MSCD001 

If you need more conventional memory, you might want to replace it with an alternative redirector, like SHSUCDX that you can download on that page I linked earlier. Just download it, copy it inside C:\WINDOWS and replace the MSCDEX.EXE with SHSUCDX in AUTOEXEC.BAT