HDD constantly reading?

[SlickShoes]

Since I sorted out my insane fan noise I have now noticed my HDD is constantly making noise, all it holds is data, even when I am not using it the hard drive light on the front of the computer is blinking and I can hear it making the usual grindy read/write noises. It is a seagate barracuda 7200 rpm 250GB, anyone got any ideas?

 

[SlickShoes]

And I have just fixed it already by going to services.msc and turning off Windows Search Indexing, now it's silent again. Problem solved!