Monitoring MS-DOS Applications

In Windows 2000, each MS-DOS application runs in its own NTVDM process, eliminating some of the problems encountered in 16-bit Windows applications. All of the NTVDM processes are called Ntvdm.exe by default, but you can use the following procedure to change the name for easier tracking.

To create a new process name for an NTVDM process

1. Copy Ntvdm.exe to a file with a different name.
2. Change the value of the cmdline entry in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\WOW to the name of your copy of Ntvdm.exe. The default value is systemroot\System32\Ntvdm.exe.
3. When you start an MS-DOS application, it will run in a process with that name. Figure 5.16 shows how your edited process name appears in Regedt32.

Enlarge figure

Figure 5.16 New Process Name in Regedt32

Tip

You do not have to restart the computer for the registry change to take effect. Thus, you can change the registry between starting different MS-DOS applications and have each start in a uniquely named process. It is also prudent to set the process name back to Ntvdm.exe when you are finished.

If you are not satisfied with the performance of your MS-DOS-based applications in Windows 2000, try changing the following settings, accessed by right-clicking the file in Windows Explorer:

• Under Usage in Screen properties for the .pif file, select Full-Screen to speed up video display performance. Press ALT+ENTER to get in and out of full-screen mode.
• Disable the Compatible Timer Hardware Emulation feature in the _Default.pif or the application's program information file (PIF). To disable it, clear the check box displayed when you click the Windows NT button under Program properties for the file. Because this feature causes a decrease in performance, use it only if it is required to allow an application to run under Windows 2000.
• If the application is in a window and seems to pause periodically, try reducing idle sensitivity by moving the Idle Sensitivity slider to the left in Misc properties for the application's .pif.
• If the MS-DOS-based application can be configured for printing, choose LPT1 or LPT2 rather than parallel port. Most of the applications use Int17 to print when configured for LPT. If you select parallel port mode, these applications print directly to printer ports. Parallel mode is significantly slower in Windows 2000 compared to Windows 3.x.

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