Have you updated and run the programs?
I've had problems with my harddrive on my HP ENVY Desktop windows 8-computer (i7 quad core processor, 1 tb harddrive, 8 gb RAM, and 2 gb grapichcard) in a couple of months now. Often when I leave the computer without any processes on, it says in the task manager that my disk works with 100 % active time. In the most cases this results with that my computer hangs and I must restart it. It's getting more irretating for each day because I can never be sure of if the computer will work fine or not, because these 100 percent disk activity spikes come completely randomly. I've disabled all antivirus software, run ccleaner and chkdsk, checked and updated to the latest drivers, formatted my computer, turned off windows update, changed the virtualization memory and also disabled hard drive indexing. No of these things improved my computers performance. But on the other hand these disk usage spike never appear when I boot my win-computer in safe mode, both in minimal and network mode.
So, may this be a hardware problem or has it something to do with software issues?