Control Panel > Sounds & Audio Devices, Sounds tab?
When you double click the Speaker icon in the Notification Area, (System Tray), are any of the options muted?
Ok, all my sounds work fine but when I set a sound to play for my system like recycle or minimize, the sound doesn't play.
I'm using XP and my computer Sony viao is not even 2 years old yet. Hope someone can help me with this. It's been going on for about 2 months now.