Imports System.Runtime.InteropServices
 
    <DllImport("winspool.drv", SetlastError:=True, CharSet:=CharSet.Auto)> _
    Private Shared Function SetDefaultPrinter(ByVal pszPrinter As String) As
Boolean
    End Function
 
    SetDefaultPrinter("name of printer")

	Private Sub SetDefaultPrinter(ByVal Printername As String)
		Dim moReturn As Management.ManagementObjectCollection
		Dim moSearch As Management.ManagementObjectSearcher
		Dim mo As Management.ManagementObject
		moSearch = New Management.ManagementObjectSearcher("Select *" & _
  "from	Win32_Printer")
		moReturn = moSearch.Get
		For Each mo In moReturn
			Dim AktPrinter As String = mo("Name")
			If (AktPrinter = Printername) Then
				mo.InvokeMethod("SetDefaultPrinter", Nothing)
			End If
		Next
	End Sub