Windows 8 Disk Usage Keep up 100%

Recently i find the windows8 Disk Usage always keep up 100%, It must be have some issue.
Step1. Go into Open Task Manager
Step2. Go to Details tabStep3. Right click the columns headers and click "Select Columns"Step4. From the "Select Columns" window, check: I/O Reads, I/O Writes, I/O read bytes, I/O write bytes --> click OK, Now you can clear view which service stay up your performance.
I found the "windows search" service is the biggest I/O,
in the "services.msc" stop it auto start.