Nope, that didn't do anything. Although it's less busy now, the drive light still pulses constantly even at the desktop with nothing running except MSE in the tray.
Here's a screenshot with that service stopped, and only Firefox, Task Manager and Resource Monitor running. I'm starting to wonder if I borked something when I resized the partition to install Linux (I defragmented first though, and it let me shrink it down so there can't have been anything in it's road, right?).
EDIT - sfc didn't find any errors, so perhaps not. Hmm.
EDIT2 - Neither did chkdsk.