Your computer will restart into a special recovery environment and perform a deep 15-minute scan to remove threats that hide while Windows is running. When to Use the Legacy 64-bit Download
Plug in a blank USB drive (at least 4GB) or insert a blank CD/DVD. download windows defender offline 64-bit
How to Download and Use Microsoft Defender Offline (64-bit) Microsoft Defender Offline is a powerful scanning tool that runs from a trusted environment without starting your operating system. This is specifically designed for situations where a rootkit or other highly persistent malware is preventing your normal antivirus from working correctly. Your computer will restart into a special recovery