Mark Junker wrote: > BTW: How does the "serenum" stuff works? Serenum is an upper-level device filter driver. It is used to enumerate devices connected to serial port. Together serial and serenum provide functionality of a PnP bus driver. There is a "Serenum Driver Reference <senumref_1a4b2c57-95f0-488d-9fda-75a294e1495b.xml.htm>" in DDK.