Hi everyone, the DDK-documentation specifies that IUnregisterSubdevice is only available from XP SP2 onwards. But I have found a reference in here http://msdn.microsoft.com/en-us/library/ff536345(VS.85).aspx that a hotfix exits to also allow W2K to use dynamic topologies. Does anyone have experience with this and knows which hotfix is necessary to get this going? Best regards, Tobias ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.com/