I never use such a thing. I look at my machine and then head to the maker of my computer or motherboard.
In XP however the most common cause I encounter for crackling is the old XP DMA BUG. This was NEVER resolved by MSFT and the fix is easy, required no install or reboot. Try it now at http://winhlp.com/node/10
Some don't want to do this or want a long explainer. Sorry but it's a very common issue worth about 3 minutes and it's gone. Why go any deeper?
OK, i have this problem.. I had crackling with the music and I thought it was the driver. I uninstalled it (I had SoundMax Integrated Digital Audio). THan I wanted to install it again with Driver Reviver. It shows me AC97 driver and when it installs it gives me BSOD. I gave no sound and in Device Manager, there is triangle with exclamation mark in it and it says Multimedia Audio Controller. And in driver details it gives me Realtek AC97. I ran everest and the motherboard is Foxconn AwardAcpi, thats what it says. Thanks in advance. BTW I reinstalled the Windows (its XP SP3) and it gives me again that error.