PC Hardware —

MS-DOS-Application Incompatibilities

In spite of attempts to make Windows 95 backwardly compatible, it can still experience problems running MS-DOS applications. Most MS-DOS applications run better in Windows 95 than in Windows 3.11, but very few users pushed the envelope by running MS-DOS applications with earlier versions of Windows. (Most users simply updated them and learned to use the new software.) Often, MS-DOS applications refuse to run under Windows 95 (and Windows 98) because they cannot find a version of MS-DOS they recognize.

"Wrong MS-DOS Version"

One of the most common causes for MS-DOS- and Windows-application crashes in Windows 95 is that many applications check the version number of MS-DOS before running. If the software reads the wrong version number or a version number that's in the wrong range, an error occurs and the program crashes. To get around this, Windows 95 "lies" to applications and passes the right version number.

To achieve this, Windows needs a bit of help tricking MS-DOS programs. Include the following line in the CONFIG.SYS file. Remember, lines in the CONFIG.SYS overwrite IO.SYS and SYSTEM.DAT commands:

 device=c:\windows\setver.exe

With SETVER.EXE loaded, Windows 95 will report an appropriate version number to your MS-DOS application.

Tricking an old Windows 3.x application is a two-step process.

First, find the module name for the application that is crashing. To find an application's module name, start Windows Explorer and then right-click the application's executable (.EXE) file. Using Quick View, find the module name. For example, the module name for Word 6.0 is winword.

NOTE
QuickView is not included in a typical Windows 95 installation. To load QuickView, go to the Control Panel and select the Add/Remove Programs applet. In the Add/Remove Programs dialog box, select the Windows Setup tab, then select Accessories. Click the Details button, check QuickView on the Components list, and click the OK button.

Next, add a section to your Windows 95 WIN.INI file. Open WIN.INI using a text editor and add the following lines:

 [Compatibility]
  compiled_module_name = 0x00200000

For example, you would add:

 winword = 0x00200000

Other MS-DOS Workarounds

Often, MS-DOS applications fail to execute because of missing drivers or the presence of Windows itself. By using the Properties tab of a program's .EXE file, you can modify many of the settings that cause your program to fail. To do this:

  1. Open Windows Explorer and find the troublesome MS-DOS .EXE file.

  2. Right-click with your mouse and select Properties.

  3. Click the Program tab.

  4. Click the Advanced button.

The Advanced dialog box will present the following options:

  • Prevent MS-DOS-based Programs From Detecting Windows: This hides Windows in memory so MS-DOS programs can't detect it.

  • Suggest MS-DOS Mode As Necessary: This is an on-the-fly MS-DOS-mode diagnostic. If Windows detects an application that's likely to run better in MS-DOS, it starts a wizard so that you can customize the application to run in MS-DOS.

  • MS-DOS Mode: If this option is selected, the application will run in MS-DOS mode. Within this setting are three additional options:

    • Warn Before Entering MS-DOS: When entering MS-DOS mode, you should close any open Windows applications and files. This warns you to save files and close any applications that are running.

    • Use Current MS-DOS configuration: This uses all the current system settings that have been passed along, including settings in CONFIG.SYS, AUTOEXEC.BAT, IO.SYS, and the Registry.

    • Specify A New MS-DOS Configuration: This allows you to modify CONFIG.SYS and AUTOEXEC.BAT for MS-DOS mode.

This Properties tab is the Windows 95 replacement for the .PIF files used in Windows 3.x. You will find five other tabs for configuring the properties of this MS-DOS application. These tabs are:

  • General: Provides the statistics of the file.

  • Font: Specifies the type of font you want to use.

  • Memory: Configures expanded and extended memory requirements.

  • Screen: Offers options for running inside a window or full screen.

  • Misc: Provides miscellaneous settings.