Monitoring legacy programs
This topic describes how to monitor a 16-bit Windows-based program or an MS-DOS-based program.
In , 16-bit Windows-based programs run as separate threads in a multithreaded process called Windows Virtual DOS Machine (NTVDM). The NTVDM process simulates a 16-bit Windows environment. An MS-DOS-based program runs in its own NTVDM process.
You can monitor a 16-bit program or an MS-DOS-based program running on your computer with System Monitor by monitoring the ntvdm instance of the Process performance object. Note that 16-bit programs running in an NTVDM appear only if they are started in a separate memory space.
If you find that your 16-bit programs are not performing well under , you can access some of the program's properties by right-clicking the name of the program in Windows Explorer and configuring the properties as follows:
It is possible to turn off Compatible Timer Hardware Emulation for the program if performance does not improve by changing the previously described settings. To do so, right-click _Default.pif or the program name, point to Program, and click Windows NT. In the dialog box that appears, clear the Compatible Timer Hardware Emulation check box. This change typically causes a decrease in performance and should be made only if other efforts fail.