I've had more probs with win7 and audio stuttering than every before, so I happen to have been working on this lately myself.
Anyway, my best advice is to use this dpc latency checker and disable your devices one at a time to find out which one is giving windows a stutter. Mine was a wireless card, and network drivers are quite often suspect, so might want to start there.
http://www.thesycon.de/deu/latency_check.shtml
once you find what is giving windows the problem, you can proceed accordingly, or given it's a laptop, bitch at hp accordingly
