Hi, I want to reocord/spy all the outgoing system sound to a file,in order to implement such a spy i have learned that i need to write a virtual audio driver that inserts itself into stack of audio drivers and just pass the data it receives to lower driver along with writing it to file. Where will this virtual driver be inserted in the stack ? There are class/mini class drivers , port/miniport driver. Where to fit my filter in this stack and how ? Is there any sample i can look at ? There is MSVAD in XPDDK but its implementing a miniport driver serving as an example for driver writer to write audio drivers but not an example of a filter driver that gets inserted in the stack. any help would be highly appreciated. Regards Raza ****************** 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.de/