Munch's Oddysee (Steam/PC) sound problem

[Queen Skillya]

There is this really annoying static-like sound in the background.

OS: Windows XP SP3 32 bit, of course
Video: NVidia Quadro 770M (in an ancient laptop)
IntelvPro Core

[Varrok]

Unplug your mic

[Queen Skillya]

Unplug your mic

Impossible to do since it's built into the laptop. Disabled it from control panel and annoying sound still exists intermittently.

[Varrok]

When you open your Sound Mixer (via PPM on volume icon in the traybar and LPM on the button) isn't there anything else that might cause the noise?

[Queen Skillya]

No, and that's why it has me doing the infamous Abe shrug

[Varrok]

Are your sound drivers up-to-date? Video-audio codecs? ...sound quality (in control panel -> sound -> speaker properties -> advanced)?