I have developed a customizable WDM audio miniport driver based on portcls. Driver customization consists of selecting driver/device names and some other parameters, such as topology node names/GUIDs in MediaCategories. To maintain MediaCategories, I use unique GUID set: xxxxxxxx-xxxx-11db-bc7a-00001b40b067. First two parts are unique for each driver configuration and each topology node. When driver is installed, it creates entries in MediaCategories for each topology node. When driver is uninstalled, it deletes these entries. When I tested two different configurations installed together, they worked fine. I checked GUID created, and there were no errors. First driver configuration created "Line 1" and "Line 2" entries for capture and render categories (both KSNODETYPE_LINE_CONNECTOR types) and second driver configuration creates "Mixout 1" and "Mixout 2" entries. While both drivers are installed simultaneously, all nodes and endpoints are visible with their correct names. But when I uninstalled first driver configuration (which uses "Line N" names), I see "Mixout 1" and "Line 2" endpoints. Opening the "Line 2" device properties in the Sound panel, I see "Line 2" at General tab and "Mixout 2" at Levels tab. I checked MediaCategories branch, and there was no entry named "Line 1" or "Line 2". There was only proper GUIDs created by second driver configuration with "Mixout N" names. Second driver module has no "Line" substring at all so it cannot erratically generate a wrong name. When I restarted AudioEndpointBuilder service, the names became correct. I'm afraid AudioEndpointBuilder either has a kind of hash, keeping hashed values instead of GUIDs, or compares not all GUID bytes. It is the only possible explanation :( Microsoft guys, could you please comment this issue? If needed, I can place a bug report at Microsoft site. I use Vista SP1 Ultimate English 32-bit. Regards, Eugene ****************** 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/