Posted 12 December 2009 - 04:22 PM
Control Panel/Sounds and Audio Devices. Open it up. Click on Sounds tab.
If you want no sound from anything, use the drop down arrow in Sound Scheme and set to No Sound, then click Apply.
If you only want to disable clicking noise when opening a folder, there are a bunch of things listed under Program events.
I'm not sure which one, if any, will disable it, you'd have to use a process of elimination and trial and error to narrow it down.
As for AIM, you'll have to open it up and go through it's preferences to find where you turn off notifications.