This is a disk usage reaching 100% fix if this helped you drop a like on both the topic and the videoif it did not work contact me for another solution https://www.youtube.com/watch?v=tpGhUQ7BBDM&feature=youtu.be
Why.. In the world would you ever turn off automatic updating? Firstly if your PC is exceeding 100% PC usage, you most likely don't meet the recommended requirements for Windows 8. I would advise no one to turn off windows updates, if windows 8 is moving slow for you, please downgrade to 7. Turning off automatic updates could cause machine trouble and firmware problems. Also turning off windows search gets rid of the search function meaning you won't be able to find anything unless you manually dig. However it will slow down your usage, as windows search uses quite a bit of memory, so that helps. But I would advise against turning off windows automatic updates.
I Understand were your coming from but this is what the Microsoft Support Team Suggested me to do as it was the cause of the problem. And i asked several Support Team members and they all suggested the same thing.