Visual Basic

 <DllImport("mpr.dll", SetLastError:=False, CharSet:=CharSet.Auto)> _
Friend Shared Function WNetGetUniversalName( _
ByVal lpLocalPath As String, _
ByVal dwInfoLevel As Int32, _
ByVal lpBuffer As IntPtr, _
ByRef lpBufferSize As Int32) As Int32
 End Function

 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
     Dim bufSize As Int32 = 2000
     Dim bufPtr As IntPtr = Marshal.AllocHGlobal(bufSize)
     Dim sMapPath As String = "Z:\"
     Dim ret As Int32 = WNetGetUniversalName(sMapPath, 2, bufPtr, bufSize)
     If ret = 0 Then 'ERROR_SUCCESS
         Debug.WriteLine("This is a Mapped Network Drive " & ret)
     End If
     If ret = 1200 Then 'ERROR_BAD_DEVICE
         Debug.WriteLine("The specified device name is invalid. " & ret)
     End If
     If ret = 2250 Then 'ERROR_NOT_CONNECTED
         Debug.WriteLine("This network connection does not exist. " & ret)
     End If
     Marshal.FreeHGlobal(bufPtr)
 End Sub

' Retrieve the working rectangle from the Screen class
' using the PrimaryScreen and the WorkingArea properties.
Dim workingRectangle As System.Drawing.Rectangle = _
    Screen.PrimaryScreen.WorkingArea

' Set the size of the form slightly less than size of
' working rectangle.
Me.Size = New System.Drawing.Size(workingRectangle.Width - 10, _
    workingRectangle.Height - 10)

' Set the location so the entire form is visible.
Me.Location = New System.Drawing.Point(5, 5)