Windows 10 has alerts to encourage Firefox users to use IE

Re:Windows 10 has alerts to encourage Firefox users to use IE by synackrst on Thursday January 19, 2017 @11:30AM (#13437032)

You can install OS X / "Core" updates (but not updates for apps that you've installed via the App Store) via the `softwareupdate` command line utility [0]. It's not at all ideal for an everyday user, but would work if you wanted to avoid the App Store entirely.