C#

[DllImport("setupapi.dll", CharSet = CharSet.Auto)]
<span style="color:#0000ff;">static</span> <span style="color:#0000ff;">extern</span> IntPtr SetupDiGetClassDevs(           // 1st form <span style="color:#0000ff;">using</span> a ClassGUID
   <span style="color:#0000ff;">ref</span> Guid ClassGuid,
   IntPtr Enumerator,
   IntPtr hwndParent,
   <span style="color:#0000ff;">int</span> Flags
);

<span style="color:#0000ff;">static</span> Guid DiskGUID = <span style="color:#0000ff;">new</span> Guid("GUID_DEVINTERFACE_DISK");

<span style="color:#0000ff;">static</span> <span style="color:#0000ff;">void</span> Main(string[] args)
{
    IntPtr h = SetupDiGetClassDevs(ref DiskGUID, IntPtr.Zero, IntPtr.Zero, 1);

    //Console.WriteLine(h);
    Console.ReadKey();
}