My problem is that starting at a random playback instance (starting a song in an mp3 player, a video or sound object on a web browser, TTS or voice events in a VoiP program), my sounds will cease to begin.
An example of my problem would be Windows properly booting, playing the startup and login sounds, then permission sounds to allow certain programs to run. I'll start Zune and then may or may not be able to start a song. If the song can't start, the timer will remain at 0:00 of the duration of the song even if I adjust the progress bar of where the playback should be in the song. However, sometimes the song will start. Then I may start Ventrilo, and connecting to a server and attempting to play the "Connected to server" TTS event will freeze Ventrilo and force me to shut it down. The mp3 will still play, but once it stops, no longer can I play any more songs, even the one that was just playing. Nor will I be able to play a YouTube video on Firefox.
An interesting note is that when this problem begins, if I try to right click the Volume Control at the bottom right and bring up Playback Devices, the loading circle will appear on the cursor for a moment, then disappear, but no window will pop up. Before the problem starts this window is accessible.
I also get random crashes when starting some games like Call of Duty 6: Modern Warfare 2 or Heroes of Newerth, sometimes accompanied by video distortions, other times not. Neither game will crash in the menu, but once gameplay attempts to begin, problems may or may not arise. Typically if the first five minutes of gameplay pass without trouble, the game will continue to run flawlessly for any period of time. Even a sound event like receiving an instant message on Pidgin can start the problem, and then I can use no programs that require sound, even trying to audibly hear a coded word for the SevenForums registration.
I have tried:
Reinstalling my graphics drivers
multiple times, with varying levels of success and failure.
Fixing my missing coprocessor issue by installing nVidia SMU drivers, which actually increased the frequency of failure.
Restarting thousands of times..
Starting programs in a different order (desperate).
Nothing seems to work. This problem did not always exist. The first few months of Windows 7 Home Premium x64 were flawless, but now my computer is so encumbered by this problem it has unreliable and hardly usable.