Why do you blame Windows right away? It's a specific issue to one PC. Now, what model of PC or motherboard if custom built? Does it still happen with default Windows driver (uninstall audio driver), or running an Ubuntu boot disk? As to the latter, you can download Ubuntu free, then run the OS from the CD without installing to a HDD by selecting "Try Ubuntu" at the choice screen.
If that PC has crackly sound even outside of Windows, that points to an issue with the audio hardware.