This is interesting...

 Code:
setdefaultprinter(lcase("\\Server\Brother HL-2270DW series"))

sets the registry to an all lowercase printer, and you have to refresh/F5 to see the default printer change in GUI.

 Code:
Dim $net
$net = CreateObject("wscript.network")
$net.SetDefaultPrinter(lcase("\\Server\Brother HL-2270DW series"))

sets the registry ignoring the lower case function and sets it to match the name in the GUI. The GUI automatically switches the default without having to refresh/F5.