Having tried this solution and many others suggested on various sites which worked in the short term but always reoccurred the next time computer was powered up. I found that changing Windows Update from starting automatically to manually solved this problem for me.
Enter 'Services' in search bar and choose 'Services (Desktop app)'
Scroll down to 'Windows Update' right click on the Windows Update line and choose the 'Properties' option
In the 'General' tab go to the Startup type and in the drop down option box choose 'Manual'
Click on 'Apply' followed by 'OK'
Hope this helps.
My computer already had it on MANUAL and still it shows Disk 100% anyway.