I tried doing a restart, but it wouldn’t work. The other day, I was trying to turn on my Windows Defender, but it didn’t work. Happy Reading! Really glad that you are here. Do let us know how you feel about it in the comment section below. It shares basic information about this article and also adds more value to it. Hey there! Before reading the article which is about Windows Defender won’t turn on Windows 10, you should read about windows defender won’t turn on windows 7.