Public Class Form1
    Private Declare Function FindExecutable Lib "shell32.dll" Alias _
        "FindExecutableA" (ByVal lpFile As String, ByVal lpDirectory _
        As String, ByVal lpResult As String) As Long
 
    Private Function StandardBrowser() As String()
        Dim sExe As String
        Dim tmpFile As String
        Dim dNr As Integer
        Dim Browser(2) As String
 
        tmpFile = Application.StartupPath & _
            "\xxx.html"
        dNr = FreeFile()
 
        My.Computer.FileSystem.WriteAllText(tmpFile, "", False)
 
        sExe = ExePfad(tmpFile)
        My.Computer.FileSystem.DeleteFile(tmpFile)
 
        If sExe <> "" Then
            If InStr(LCase$(sExe), "iexplore") > 0 Then
                Browser(1) = "Microsoft Internet Explorer"
            ElseIf InStr(LCase$(sExe), "netscape") > 0 Then
                Browser(1) = "Netscape Communicator"
            ElseIf InStr(LCase$(sExe), "opera") > 0 Then
                Browser(1) = "Opera"
            Else
                Browser(1) = "kein Browser installiert."
            End If
        End If
 
        Browser(0) = sExe
        Return Browser
    End Function
 
    Private Function ExePfad(ByVal Datei As String) As String
        Dim Pfad As String
 
        Pfad = Space$(256)
        FindExecutable(Datei, vbNullString, Pfad)
 
        If Pfad <> "" Then
            ' Pfad = Left$(Pfad, InStr(Pfad, vbNullChar) - 1)
        End If
 
        If UCase$(Pfad) = UCase$(Datei) Then Pfad = ""
        ExePfad = Pfad
    End Function
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim browser() As String
        browser = StandardBrowser()
        Label1.Text = browser(0)
        Label2.Text = browser(1)
    End Sub
End Class