X30: HDD LED always on, with very slow performance...

[Quattro]

all of a sudden. The hard drive LED is always on, and the computer barely responds. The last two boots it would do this for 5-10min, then return to normal operating speed, now it won't respond normally at all.

No strange processes in task manager. System is running at normal temp. Symptom of a dying HD? CPU usage will spike to 100% briefly for some weird reason. Tried disabling any unecessary hardware. System specs in sig.