Regular updates are critical to the effectiveness of a virus scanner, and Windows Defender is no exception. However, how this Windows-integrated scanner acquires these vital updates is very different from third-party scanners. Instead of offering an update scheduler, as most other scanners do, Defender relies on Windows 8’s Automatic Updates feature to search for and install virus definitions.
That is all well and good for systems with Automatic Updates enabled, but many people dislike the mandatory reboots that come with this automation, not to mention the lack of choice in which updates are applied. If you are one of the many who prefer greater control, you might well have Automatic Updates disabled so that you can manually choose what is updated and when. The problem is you probably don’t update your system as often as you should update your virus and spyware definitions, so your system is potentially vulnerable.
Windows Defender includes a prominent Update button so you can manually update the scanner without committing to a system update, but really, how often do you actually click that button? Probably not every day and maybe not every week, which is why scheduling regular updates is so important to maintaining an up-to-date virus scanner. However, without a scheduler built into Defender, you will need to set regular updates in Windows 8’s Task Scheduler, which allows updates even if Automatic Updates are disabled.