Important: Windows Defender will turn off if you install another anti malware program to protect your PC. For more information, see Protect your PC. You should carefully investigate the source of anti malware and other products before downloading and installing them. Many companies, including those listed on this page, distribute anti malware software. For business security software that is compatible with Windows, please contact your security vendor of choice.

Just click the company name to see the Windows-compatible product they offer. Should you wish to explore alternatives to the already installed or available Microsoft antimalware software on your Windows PC, the reputable security companies listed below provide consumer security software that is compatible with Windows. Hackers and scammers sometimes use fake antimalware software to trick you into installing viruses or malware on your computer. Windows Defender is free and is included in Windows, always on and always working to protect your PC against malware. Malware consists of viruses, spyware and other potentially unwanted software. If you’re running Windows 10, Windows 8.1, or Windows 8, you’ve already got Windows Defender built in, helping to protect you against viruses, spyware, and other malware.