Install a CD Driver for DOS



Q:What is MSCDEX? I can't play a game I just bought because the
 computer can't find the drivers in DOS and it says something
 about MSCDEX? Help! 

-- phone call from Justin in Ridgecrest, California 

A: MSCDEX stands for Microsoft CD Extensions. This file allows
 your operating system to talk to your CD-ROM drive. 

CD-ROMs file information differently than your hard drive does.
 Because Microsoft designed DOS and Windows 3.1 before CD drives
 became common, they need special instructions in order to
read-- and write-- CD-ROM data. Windows 95 and 98, which came out
 after CDs became popular, have these instructions built in. 

You'll need to follow these steps to teach your older OS to work
 with CDs. Don't worry, we'll go into each step in detail in the
 next few pages. 

Find the DOS driver, also called the "real-mode" driver, for
 your particular CD ROM drive. 
Install the driver. 
Edit the config.sys file to add the information about
 your CD type. 
Edit the autoexec.bat file to point to the newly installed driver

Find and Install the Driver

Before your computer can recognize your CD-ROM drive, it needs a
 driver to show it the way. You will find this file on the
 original installation disk that came with your CD drive. If
 you've lost the disk, try the drive manufacturer's website, or
 stop by www.windrivers.com and search for the brand name and
 model of your CD drive. 

When you find the driver, download it to your computer and
 install it.

Edit config.sys

Editing your config.sys file is not as scary as it sounds. All
 you're doing is telling this file where it can find the driver
 for your CD-ROM drive. 

Use the Find command in the Start Menu to locate your config.sys
 file. Before you do anything else, make a copy of config.sys
 onto a floppy disk. (You never can be too careful.) 

Open the config.sys file on your hard drive and look for a line
 that begins: 

Device= 

Plug in the name of your CD-ROM driver, like this: 

Device=atapi_CD.sys 

You also need to tell config.sys to look for the CD somewhere
 other than on your hard drive. You thus assign your CD drive a
 letter and a name. Let's assign it to Drive D, and name it
 MSCD001 (which is often the default.) 

Device=atapi_CD.sys /D:MSCD001

Edit autoexec.bat

You're almost done. The config.sys file now knows where to find
 your CD-ROM driver and what to call it. It's time to let your
 Microsoft extensions know as well. 

Make a copy of autoexec.bat onto a floppy before you open it. 

Now open autoexec.bat on your hard drive. You want this file to
 launch MSCDEX.exe at startup and to point to the newly installed
 CD driver. All you need to do is add this line to the file: 

C:\windows\commands\MSCDEX.exe /D:MSCD001 

Next time you restart your computer and launch DOS, the machine
 should be able to find your CD-ROM drive.
