I was running the free version on my pc...64bit windows 8.1. and I updated to win 10 and didn't have any issues. I recently paid for a subscription to Internet Security version and started having problems....first was "critical error -start menu and Cortana not working" I thought I had a work around by avoiding the Edge (MS browser) and using Chrome but then started having printer problems. I uninstalled the paid version and was able to revert to free version and all seems normal now although I haven't done much testing yet. I tried to call Avast but they no longer seem to have a working phone number which is a cause of concern. My question is do they have a new phone number and number 2 is are there compatibility issues with their Internet Security software and windows 10? Lastly I read some negative posts about their accounting dept or lack there of so I want to make sure I'm not on an automatic renewal which I don't see an option for in my account I set up.