Q. I see versions of this question asked in a couple of places, but no meaningful answer from Microsoft. So I thought I would ask it under the appropriate heading for my case:

I run Windows 10 Home 64 bit, and I often get a problem on startup. My hard disk gets hammered for about 10 minutes, and the culprit is CompatTelRunner.exe. At the same time that this process is “scanning” a load of files on my hard disk, it appears to be sending out a large amount of information via my internet connection.

This activity slows my PC right down, and sometimes it’s so unresponsive I just have to go make a cup of coffee before I can start doing anything with my machine. This is obviously unacceptable, so I’d like some answers please:

(1) What is CompatTelRunner.exe and what is its specific purpose?

(2) Why is it apparently scanning so many files on my hard disk?

(3) What information is it sending over the internet, and to who?

(4) How do I stop it from running (preferable), or how can I allow it to run, but in a way which does NOT cripple my PC for ten minutes on startup?

Answer.

I have now deleted both entries under “Application Experience”, so I hope this will fix things. If the solution works, I will try to remember to report back here and click on “Solved my problem”.