According to the product listing description, Microsoft Defender will be the app to control the antivirus “across operating systems, including Windows, Apple, and Android,” which could indicate that this may not be a replacement for the Windows Security app. Instead, it could be a new anti-malware service with additional features that might be offered through a standalone subscription like other products, such as Symantec, Bitdefender, etc., or as an additional feature for Microsoft 365 users. You may be able to download and install the app, but clicking the Get started button will prompt you to sign in with a Microsoft account. However, since the app isn’t officially available, you won’t be able to sign in. The product listing also says that you will need at least Windows 10 version 2004 or higher if running Windows on your computer. Since this is a product page in the Microsoft Store, there are no details about the requirements for macOS or Android. However, new products from Microsoft usually only support the three most recent versions of an operating system. All content on this site is provided with no warranties, express or implied. Use any information at your own risk. Always backup of your device and files before making any changes. Privacy policy info.