I have a Acer Aspire 5315 windows Vista..I experience a Popping sound When I boot up and log down my computer..It happens with the onboard speakers, as well as my 60watt speakera and also headphones...I don't know what to do, because it has been driving me bonkers for quite some time.. My Audio is realtek HD Audio.... I been having the problem for a couple of years now.. When my computer is playing audio and Video files it is fine, only on startup and logdown...

The popping is typically from the power supply kicking on and off to the sound card.

Do you experience hissing or whining noises when the CPU is changing loads? If so, you're either getting noise from the motherboard or the power supply.

Sometimes changing the sound card can make a difference but I think most of the time its due to poor build quality on motherboards / PSUs.

As far as how to fix it, I'm not sure there is anything simple. Could be the card or MB or PSU, in my experience.