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Code:
Private Declare Function GetVersionExA Lib "kernel32" _
         (lpVersionInformation As OSVERSIONINFO) As Integer
    
Private Type OSVERSIONINFO
       dwOSVersionInfoSize As Long
       dwMajorVersion As Long
       dwMinorVersion As Long
       dwBuildNumber As Long
       dwPlatformId As Long           '1 = Windows 95.
                                      '2 = Windows NT

       szCSDVersion As String * 128
End Type

Private Sub Command1_Click()
Dim X As Long
X = getVersion
If X = 1 Then MsgBox "WIN95"

If X = 2 Then MsgBox "WINNT"

End Sub
Public Function getVersion() As Long
     Dim osinfo As OSVERSIONINFO
     Dim retvalue As Integer
     osinfo.dwOSVersionInfoSize = 148
     osinfo.szCSDVersion = Space$(128)
     retvalue = GetVersionExA(osinfo)
     getVersion = osinfo.dwPlatformId
End Function