Hi All, I just installed WinXP Pro all went great but i notice my hard drive light goes on every once and awhile for no reason, im doing nothing but looking at my desktop

Somtimes it blinks like crazy moving files or something? Why does XP access my HDD for no reason? Don't know if i like XP thrashing my hard drive all the time. Theres no NIC card yet installed and it has never been online.
Thank's for your time!!
Nemises....