I've got a problem which has started only on the 10th December (same day as the Windows December update) where the Windows startup sound occurs aprroximately 14 minutes after Windows loads. Yet everything performs exactly how it should, I even play GTA IV and hear the sound whilst playing it. I've done a system restore but that doesn't seem to work, I can't pinpoint which update may have caused it but it's a rather odd problem - any suggestions? EDIT: Huh? I just heard the sound again, 31 minutes after startup?!
If everything else works... I'd be tempted to just delete the sound file. It sucks anyway. When you say you did a restore, you mean from a point PRIOR to the updates? If so, surely it's not the updates. Have you installed anything else, other than the updates?
You don't need to delete the sound file, you can disable it. Look in the Sound panel under the Sounds tab. This is definitely strange. Check your HDD for errors and set it to auto correct (a reboot is required). Make sure your HDD is defraged. User Microsoft autorun utility to see if anything strange loads up at any point in time (http://technet.microsoft.com/en-us/sysinternals/bb963902.aspx). Be CARFUL with this tool, you could prevent Windows to boot. Make a Windows complete PC backup or restore point before playing with this tool. Look in the device manager if every hardware is properly detected, and that your sound card works perfectly.
Vista has the infamous "fixed" start-up sound hidden in a dll. Changing it to a silent wav file is possible.
