I have been having problems with disk utilization in Windows 8 for quite some time. I went through numerous proposed solutions, but none of them worked.
I decided to write an article about this and some of the solutions I found. First article I wrote on this subject is available on this site (Windows 8 hangs due to 100% disk utilization). I thought that the problem was resolved after applying some fixes, but it was not. Some of the disk activity was reduced after the fixes I proposed in the mentioned articles, but the problem was not gone.
Moreover, when I switched from IDE to AHCI, occasionally both my disks went 100%. I decided to revert back to IDE, which, of course, did not resolve the problem. After my Windows Update stopped working, I decided that it was time to reinstall Windows. I reverted back to Windows 7 which used to work fine. However, after the installation of the new old Windows, I noticed that the spiking of disk still happened. I assumed it could not be a driver error in Windows, because this used to work in the same version.
Not wanting to reinstall once again, I upgraded to Windows 8 and most of my applications were preserved. Not surprisingly, the problem persisted.
Then I found an article (WD Green Drives Freeze Windows) that suggested that WD Green drives cause similar problems in Windows. I happened to have a WD Green drive, so I looked more into it. I found that WD Green drives spin down after 8 seconds of idle time, which could be slowing the system down. On a forum (WD Green drive? Slow update speeds? Update pausing for no reason?) I found a useful tool (Ultimate Boot CD) that allowed me to disable the spindown on the WD drive.
After applying the fix, I thought the problem could finally be solved. But it wasn’t. The disk kept spiking to 100%. I ran check disk for a few hours and it fixed some bad sectors, but the problem persisted. Then I ran some diagnostics which seemed to tire the disk out until it finally spiked to 100% and everything went blue. I had to restart the computer. BIOS could not find the disk at startup, so I finally realized that the disk was dying. The disk was only two years old, so I did not think that could be the problem. Apparently, it was. I bought a WD Black drive and installed it. Later, my WD Green started working again and I was able to salvage most of the data from it.
After I installed the WD Black, I haven’t run into the problem.