The Windows 10 slows down and always becomes unusable on my Surface Pro 3 tablet. Through the Task Manager, the Windows Compatability Telemetry (CompatTelRunner.exe) takes extremely high CPU and disk usage at 100% level. Thousands of disk reads and 3000 page are faulted by I/O other. That also happens on my Windows 8 computer. How can I fix the large performance issues?
If the Windows root directory (by default it is C:\) has less free space, the disk will be thrashing due to paging while the system can’t allocate enough virtual memory. For the hardware has not enough RAM, the solution is to buy and add more memory to your PC.
Disable CompatTelTunner.exe from Task Scheduler
* Press Win + R from your keyboard, type taskschd.msc in Run dialog box and Click OK button.
* Double click on Task Scheduler Library, and navigate to Microsoft > Windows > Application Experience.
* Go to its right side pane, Right click on “Microsoft Compatibility Appraiser”, and choose Disable. BY default this task is set to start if any network connection is available.
You can use the Process Blocker utility to block the Compattelrunner.exe application with “Block other applications with identical CRC” to get rid of it. But the latest updates of Windows 10 cause it not working.
Take ownership of the file, and remove it
* Type compattelrunner.exe in the Cortana search box or Start menu, right click on compattelrunner program and select “Open file location”.
* The File Explorer will be opened under the C:\Windows\System32 folder. Right-click the Compattelrunner.exe, and select Properties.
* Go to the Security tab, click on the Advanced button.
* Under Owner tab, click Change owner, select your current using account , and click Apply, then confirm that.
* Re-open the Properties of Compattelrunner.exe, under Security tab. click Edit option. Highlight your account, check Full Control under the Allow column, and click Apply > OK button.
Now you are able to rename or delete the compattelrunner.exe completely, without Access is denied error.
The entire update KB2977759 or KB2976978 seems to make the Windows Customer Experience Improvement Program to install. You could uninstall those updates but that may mess with the schedule of Windows Updates.