Troubleshooting CD-ROM Problems in Windows 3.1 Enhanced Mode

• Microsoft Windows operating system versions 3.1, 3.11

SUMMARY

If you experience problems with a CD-ROM drive when running Microsoft Windows version 3.1 in 386 enhanced mode, there are several steps to try to correct the problem. This article explains these procedures.

NOTE: Windows does not have any special device drivers or .INI file settings that it requires for CD-ROM drives.

MORE INFORMATION

1. If you start Windows from your AUTOEXEC.BAT file, ensure the MSCDEX command is before the WIN command.

2. Make sure the CD-ROM works at the MS-DOS level before starting Windows. To test this, use a data disk. Change the default drive to the CD-ROM. For example, type the following to change to drive E:

         E:
   

   You should be able to obtain a directory listing by typing "dir" (without the quotation marks) at the MS-DOS command prompt. This test should be used to confirm that the hardware is functioning correctly.

3. Make sure all the correct drivers are being loaded. You should have drivers loaded in both the CONFIG.SYS and AUTOEXEC.BAT files. For example, MSCDEX.EXE should be loaded in the AUTOEXEC.BAT file. The following is an example of a ProAudio driver being loaded in the CONFIG.SYS file:

         device=d:\proaudio\tslcdr.sys /d:mvcd001 /r "ProAudio CD driver
   

   For troubleshooting purposes, do not load any of the drivers into the upper memory blocks (UMB). For example, don't use LOADHIGH, LH, DEVICEHIGH, or any other UMB manager (such as QEMM or 386MAX) to load the drivers high.

4. Use the right driver versions. The following information is taken from section 11.1 of the Windows 3.1 README.WRI file:

         If you are using a CD-ROM drive with Windows 3.1, you should use
         version 2.21 of Microsoft MS-DOS CD-ROM Extensions (MSCDEX) with
         all configurations of CD-ROM drives. If you use version 2.2 or
         later, you must also remove the following setting from the
         [386Enh] section of the SYSTEM.INI file:
   

            device=LANMAN10.386
   
         This setting can cause some CD-ROM drives to time-out and fail
         with versions later than 2.2 of MSCDEX. However, if you must
         use a version earlier than 2.2 of MSCDEX, the above setting is
         required in the [386Enh] section of your SYSTEM.INI file.
   
         If a CD-ROM drive causes instability in your system or causes
         your system to fail, you may need to update the CD-ROM driver.
         Also, the Media Control Interface (MCI) driver MCICDA.DRV may
         not work properly with older CD-ROM drivers. Contact your
         CD-ROM drive manufacturer about obtaining an updated driver.
   
      Updating the Driver
      -------------------
   
      The CD-ROM driver is located in the CONFIG.SYS file. If the MSCDEX
      driver was upgraded with out upgrading the CD-ROM driver, it is
      possible that the CD-ROM driver itself is out of date. A current
      CD-ROM driver should be obtained from the original equipment
      manufacturer (OEM) of the CD-ROM drive.
   
      Using SETVER
      ------------
   
      If you use a version of MSCDEX earlier than 2.21 and you are using
      MS-DOS 5.0, you need to load SETVER.EXE from the CONFIG.SYS file.
      MSCDEX is in the default table for SETVER; therefore, you do not need to
      add an entry for this.
   
   

5. Make sure the CD-ROM can be correctly accessed from standard mode. Again, this doesn't guarantee it will work in 386 enhanced mode, but should be done to verify that the hardware is functioning correctly.

6. If problems persist, you can prevent Windows from using any upper memory block (UMB) space. Either start Windows with the /D:X parameter (WIN /D:X) or add the following line to the [386Enh] section of the SYSTEM.INI file.

         EmmExclude=A000-EFFF
   

   NOTE: If you are using EMM386.EXE or some other UMB manager, you need to use an exclude statement when loading the UMB manager because those settings will override other memory exclusion switches in Windows 3.1.