When you turn off your computer in Winxp, you know that sound that your HDD makes?

Well sometimes when I'm just surfing, I occasionally hear that noise. It didn't do that before, but it's a little disturbing considering I'm not even shutting down. Anyone else experience this "hdd shutdown" noise when the PC is ON?

I have an WDSE 80GIG and an IBM 180GXP 60gig.