Private Declare Function IsUserAnAdmin Lib "shell32.dll" () As Integer
 
    Public Function IsAdmin() As Boolean
        IsAdmin = CBool(IsUserAnAdmin)
    End Function

    Dim oUser As New System.Security.Principal.WindowsPrincipal( _
      System.Security.Principal.WindowsIdentity.GetCurrent)
 
    If oUser.IsInRole( _
      System.Security.Principal.WindowsBuiltInRole.Administrator) = True Then
        MessageBox.Show("Admin!")
    Else
        MessageBox.Show("Kein Admin!")
    End If