Zillya and Windows Defender

Zillya! runs alongside Microsoft Defender on Windows. You do not need to switch anything off, and Zillya! does not disable Defender. This page explains what Windows itself does when a second antivirus is installed, so you know what to expect.

What Windows does when you install Zillya!

Every modern antivirus registers itself with Windows Security when it installs, and Zillya! does the same. Windows then hands real-time scanning to the newly installed product and puts Microsoft Defender’s real-time protection into passive mode. Defender stays installed and stays available; it simply stops scanning files at the same moment Zillya! does. Windows is deliberately built this way, because two engines scanning the same file at once cause conflicts and slowdowns.

Do they conflict?

No. Because Windows only lets one engine hold real-time protection, the two do not fight over files. Defender can still be used for occasional manual scans through its “periodic scanning” option in Windows Security, which is off by default and can be switched on if you want a second opinion now and then.

Is a second antivirus worth it?

That depends on what you want from it. Defender is a competent baseline and it is free. A separate product like Zillya! gives you a different detection engine and a different signature database from an independent laboratory, plus modules Defender does not offer at all: a configurable firewall with per-application rules, anti-spam, a virtual keyboard for entering passwords, parental control, privacy tools and a file shredder, depending on which licence you choose. If those modules or a second opinion from a different laboratory are what you are after, that is the honest case for it.

If you want to go back to Defender only

Uninstall Zillya! through Windows Settings → Apps. Defender returns to active real-time protection on its own, usually immediately and always after a restart. Your licence key remains valid for the rest of its year if you reinstall later.

Not sure which licence you need? Read the short buying guide, or see how licence keys and activation work.