Did you look at those links I provided above?
Particularly the first one!
Although your sys specs seem more than adequate (you shouldn't be experiencing any problems there) you forgot to tell me what your soundcard is.
System Control Panel -> Device Manager -> Sound...Controllers.
I hope it's a proper card and not one of those shabby onboard chips.
You could also try the basic uninstall -> reinstall,
but when reinstalling, go for v2.79 and then install the official Winamp 2 Update
There's also a possibility that the problem is being caused by some other concurrently running software. Take a look at what else is open.
Also, it could be an IRQ conflict, eg. between modem and sound/video cards, even if it's not reported in Device Manager. Or at the worst, a resource/memory leak. Check the manufacturer's sites for updated drivers for ALL your hardware.