With Windows 8, Microsoft have integrated Microsoft Security Essentials with Windows Defender, and it comes preinstalled with Windows 8. Windows Defender provides a basic but adequate level of cover in keeping your computer protected. If you wish to install a different anti-virus product you first need to disable Windows Defender. Some antivirus products may do this automatically. If you experience any problems with the third party anti-virus, use the steps below to ensure that Windows Defender is disabled.
If you turn off Windows Defender before you install the third party antivirus product you will get a warning prompt in the Action Center that Spyware and Virus protection is turned off. This warning will disappear when you install the third party product.
Applies to: