Dear All, I have developed one audio driver based on AC97 sample code. It works fine in Windows XP. However, when I test the same driver in Vista, the audio capture is not functional for specific case. I use graphedit to test the audio driver. My driver will appear as an audio capture filter in both "Audio Capture Sources" and "WDM Streaming Capture Devices" category. The filter will capture the audio from microphone and output 8K 8bit mono audio stream. The filter located in "WDM Streaming Capture Devices" works fine in Vista. But the filter located in "Audio Capture Sources" will run for a while and stop immediately. Then one error message showed up and said "This graph can't play. Unspecified error (Return code: 0x80004005)". I compare the behavior for both filters and find out that the filter in "Audio Capture Sources" won't get a call GetAllocatorFraming(). I am not sure if it's the reason but I did get mapping from system and fill the audio data into the mapping in my interrupt service. However, the Vista just stop the audio even the first notify is not called yet. I don't know what else I need to take care. Would you please give me some suggestion? Many thanks! Best regards Jerry Pan