For debugging APOs and property page extensions I prefer to use Visual Studio 2005. WinDbg also works, but I like the debugger is VS2005. Here are a few hints: 1. Run audiosrv in its own container by doing the following from a command line and rebooting: sc config audiosrv type= own 2. In VS 2005 set the symbol file location (Tools | Settings | Debugging | Symbols) 3. Start debugging by attaching to AudioDG. (In the "Attach to Process" dialog, check two checkboxes at the bottom "Show processes from all users" and "Show process in all sessions". Leonard From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Tim Roberts Sent: Friday, June 06, 2008 5:45 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: Debugging an APO Tim Roberts wrote: I'm just digging in to the creation of a GFX APO, and I'm looking for a few debugging tips. I don't seem to see my OutputDebugString output in dbgview when my DLL is loaded into the audio engine service. I do see the messages when it gets loaded by Control Panel, but that's not the interesting case. How can I insert a new version while I'm debugging? Even if I disable the Windows Audio and Windows Audio Endpoint Builder services and disable my HDAUDIO device, my APO DLL remains loaded in one of the service host processes, and I can't copy a new version into place while it is loaded. Any debug hints from folks who have been in the trenches would be appreciated. Well, for what it's worth, I can get the debug messages if I attach a debugger to the audiodg.exe process itself. I still don't understand why the messages don't appear in dbgview. And the issue about not being able to update the DLL seems to have been a transient thing. As long as I stop the two services, I can replace the DLL just fine. -- Tim Roberts, timr@xxxxxxxxx Providenza & Boekelheide, Inc.