Even more, Microsoft and the OEMs don't really go out of their way to explain this choice to customers. I work with a senior software engineer who recently came to me for help with his new PC after having purchased the full version of the included anti-virus software. He seemed surprised when I asked why he wouldn't just stick with the built in software from Microsoft. So I sent him a link from Microsoft's site explaining about Windows Firewall and Defender. He later told me he felt stupid for having been convinced that he had to purchase the full version of what came on the system or else he would be unprotected. I think it is Microsoft who is stupid for not pushing this message harder, especially in light of the recent developments such as this one. In some of these cases, we're seeing that by installing a third-party anti-virus suite, you're actually reducing the security of your system. I think Microsoft should be concerned that these companies are actually hurting their reputation further.