My Acer Aspire 3640 doesn't have any sound.I've checked the volume and it is high.?

Answer 1

Right Click My Computer, Properties, Hardware, Device Manager.
You should find a Yellow Exclamation Point by the offending driver. Update the offending driver.

Good Luck

Answer 2

has it ever had sound? Have you pressed the mute button.
if its none of these have you been changing setting if so try system restore. if you have had sound chances are its something simple.