How to Determine If a VB App is Running Under Windows NT 3.x (122353)


The information in this article applies to:

  • Microsoft Visual Basic Standard Edition for Windows 2.0
  • Microsoft Visual Basic Standard Edition for Windows 3.0
  • Microsoft Visual Basic Professional Edition for Windows 2.0
  • Microsoft Visual Basic Professional Edition for Windows 3.0
This article was previously published under Q122353

SUMMARY

There are some scenarios in which your program should behave differently when running under Windows NT version 3.x instead of under Windows version 3.x. For example, an application based on Windows NT needs to handle networking API calls differently. Therefore it is important to find out whether or not your Visual Basic program is running under Windows NT. This article shows you how.

MORE INFORMATION

A call to the Windows API GetWinFlags function returns a 32-bit value representing the current system status. By performing a binary AND on this flag with the hexadecimal value &h4000, you can determine whether the underlying operating system is Windows NT version 3.x or not.

Step-by-Step Example

  1. Start a new project in Visual Basic. Form1 is created by default.
  2. Place a command button (Command1) on Form1.
  3. Add the following code to the general declarations section of Form1: 
       Const WF_WINNT = &H4000&
   Declare Function GetWinFlags Lib "KERNEL" () As Long

   Function IsWindowsNT() As Integer
      IsWindowsNT = (GetWinFlags() And WF_WINNT)
   End Function
  4. Add the following code to the Command1 Click event procedure: 
       Sub Command1_Click()
      If IsWindowsNT() Then
         MsgBox "You are running under Windows NT"
      Else
         MsgBox "You are running under Windows version 3.x"
      End If
   End Sub
  5. Test the program by running it and clicking the command button.
Modification Type:MajorLast Reviewed:12/9/2003
Keywords:kbenv kbhowto KB122353
©2003 Microsoft Corporation. All rights reserved.