that was a scare. hard drive started whirring on me....
it would have mostly been an annoyance. i built the pc to be modular. 1 tb total memory, over four 250 gb hard drives. rather than use something like raid, i've just left one empty. if a drive begins to die, and this hasn't happened yet, the plan is just to copy it over to the empty drive, unplug it and replace it. worst case, i might have to reinstall, but the process is automated.
as it is, a chkdsk stopped the whir and i'm not going to worry myself about it. but i blew the morning on that...