Scan your computer for malicious software before your operating system boots using Windows Defender Offline. Before scanning your computer, save and close any open files and programs. Select Start, type Virus and threat protection, and then select it from the results. Under Current threats, select Scan options. For previous versions of Windows, select Run a new advanced scan. Select Windows Defender Offline scan, and then select Scan now. Select Scan, and then, if prompted, select
Yes. The computer restarts into Windows Defender Offline and scans your computer for malicious software, which can take up to 15 minutes. The computer restarts again and Windows loads. To find the scan results, return to the Virus and threat protection screen, select Scan options, and then select Threat history. For previous versions of Windows, select Threat history on the Virus and threat protection screen.