Microsoft has released an offline virus scanner i.e. Windows Defender Offline, that was initially introduced as Microsoft Standalone System Sweeper.
Windows Defender Offline is a tool allowing you to download offline copy of Windows Defender (ISO format) and create a bootable CD/USB stick.
Windows Defender Offline incorporates a latest version of Windows PE, which is its own separate and isolated mini OS, and helps you start an infected PC and perform an offline scan to help identify and remove rootkits and other advanced malware. In addition, it can be used if you cannot install or start an antivirus solution on your PC, or if the installed solution can’t detect or remove malware on your PC.
To get started, find a blank CD, DVD, or USB flash drive with at least 250 MB of free space and then download and run the tool—the tool will help you create the removable media.
Windows Defender Offline