Windows Defender conflicts with third-party antivirus programs. Out-of-sync computer time and date. System configuration errors. Registry Editor changes preventing Defender activation. Disabled Windows Defender service
Antivirus identifies suspicious 32-bit files as generic threats. Usually indicates a Trojan Horse infection. Can download, install malware and collect sensitive data. May display aggressive ads and allow remote access
Right-click Avast icon in System Tray to disable shields control. Four options available: 10 minutes, 1 hour, restart, or permanent. Click green button to disable Avast. To re-enable, click "Enable all shields" in System Tray
Malware can infect computers and collect personal data. Unusual computer behavior, slow performance, and crashes may indicate malware. Browser redirects and unexpected toolbar items can signal malware. Background processes consuming high resources may indicate malware presence
Windows Security can scan and remove viruses from flash drives. Microsoft Safety Scanner is a free alternative for Windows 8.1 and earlier. Shortcut viruses hide files and replace them with identical shortcuts. Command Prompt can remove shortcut viruses by deleting files
Windows Defender can be activated through Windows Security's Firewall & network protection section. The active network must be selected to enable Defender. Defender can be enabled for different networks for home and work environments