Dymo labelwriter give error System.Runtime.InteropServices.COMException error com can't be registered

Question

Hi I have an error while running my little program to print a label on a 450 or 550 labelwirter. The error (some portion are in dutch):

System.Runtime.InteropServices.COMException
  HResult=0x80040154
  Message=Het ophalen van de COM-classfactory voor het onderdeel met CLSID {E8D851FA-9967-4ADF-9644-0183B9B1EA68} is mislukt vanwege de volgende fout: 80040154 Klasse is niet geregistreerd (Uitzondering van HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).
  Source=DYMO.DLS.Runtime
  StackTrace:
   at DYMO.DLS.Runtime.Printers.Init()
   at DYMO.Label.Framework.Printers..ctor()
   at DYMO.Label.Framework.Framework.GetPrinters()

fail to get the get the com factory in code:

using DYMO.Label.Framework;
foreach (IPrinter printer in Framework.GetPrinters())
LabelWriterCmb.Items.Add(printer.Name); 

What is that error. Try with regsvr32 to register the DLL but failed.
Which dll's must be in the bin dir and/or in the refence
I want to control labelwriter 450 and 550