Windows NT VDMs Keep Their Own System Time (102611)


The information in this article applies to:

  • Microsoft Windows NT Server 3.1
  • Microsoft Windows NT Workstation 3.1
  • Microsoft Windows NT Advanced Server 3.1
This article was previously published under Q102611

SUMMARY

Windows NT virtual DOS machines (VDMs) keep their own system time. Each time an MS-DOS-based application or a 16-bit Windows-based application is started, its BiosDataArea tick count is initialized to the current system time. When an MS-DOS-based application sets the time in a VDM, it is reflected in that VDM only. When a 16-bit Windows-based application changes the time, the new time is reflected in all 16-bit Windows-based applications running in Windows on Windows (WOW).

MORE INFORMATION

Windows NT is designed this way because MS-DOS-based applications depend on timer tic hardware for their sense of time. Many MS-DOS-based applications do not interact favorably with the timer tic hardware.
Modification Type:MajorLast Reviewed:11/20/2003
Keywords:kbother KB102611
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