I'm running windows 8.1. I've read several of the posts on this subject and they seem dated. The problem started when I had problems with MalwareBytes and had to reinstall it. It said to turn off Avast and reinstall MB. When I tried to turn Avast back on the error message appeared. I'm running Avast Premier. If I uninstall it where do I find the Key etc. I have run windows update but still get the error message. Thank you for your time and expertise.