Windows Audio Service doesn't start until I adjust volume

This problem has started in recent weeks (yes, too far back to do System Restore):

When I reboot, if I click on the speaker icon in the Notification Area, it tells me that Windows Audio is not running (and so no media app will produce any sound). However, if I then raise or lower the volume via my multimedia keyboard, Windows Audio starts running.

This is despite the fact that in Services, the Startup Type of Windows Audio is Automatic. So why doesn't it start on reboot?

Does Event Viewer have entries related to that service?
Event Viewer - Open and Use in Windows 7

Hmm, I didn't think to check.

The next time this symptom occurs, I will check and post the relevant events here.

even I got the same problem just recently!

I did a Google search on this problem.

Evidently it was discussed on SevenForums once before, and the consensus was that this is indeed a Windows 7 bug.

So if that's the story, we can mark this thread as "solved."

In fact, Microsoft has acknowledged that this is a Windows 7 bug:

"This behavior can sometimes occur during periods of heavy disk activity when booting to the Windows desktop. In this situation, it may be possible that even after the Windows Audio Service has been started, the speaker icon status in the notification area does not get refreshed to indicate that audio playback is functional."

I guess I should have done a Google search on this problem before wasting folks' time here.