Microsoft Defender rated best free antivirus for 2025

Microsoft Defender is identified as the top free antivirus option for most users in 2025, achieving a 99.7% score in malware detection tests. While Bitdefender Antivirus Free Edition and Avast Free also provide strong performance, Avast was noted for frequent upgrade prompts.

Regarding system management, Microsoft Defender cannot be uninstalled directly from Windows 10 or Windows 11. The standard method for replacing it is to install a compatible third-party antivirus, which automatically triggers Defender to enter a disabled mode to ensure continuous protection. Other methods to manage the software include disabling real-time protection temporarily, using Group Policy for Pro or Enterprise versions, or utilizing PowerShell commands.