Sorry to hear that.
Do you have Windows sound missing as well or just the AOL sound? Also, what is the make/model of your computer?
Thanks for the clarification.
In the circumstances, I would advise you to go to Start>Run>type devmgmt.msc >click OK. In the Device Manager window, check if there is a yellow exclamation mark against any device. Let me know the device, if any.
Also try to find the serial number of your computer if possible. Please visit the link below for guidance on how to find it:
or, use the automatic serial finder in the link below:
Keep me posted.
Ok, Click Start, then select Settings -> Control Panel. Select System applet, then Device Manager tab. See if you can check now for the yellow exclamation mark.
Ok, I'll open up your question for the other experts to offer their input.