Free antivirus from Microsoft aimed at both beginner and advanced users.

Small utility that has the functionality to protect your pen drive.
Quickly scan any file in Windows through VirusTotal via the context menu.
Portable and free tool that allows diagnosing and resolving issues in Windows systems caused by malware or other failures.
Search for all kinds of virtual pests with this excellent Russian antivirus.

Protect your computer from possible threats from USB devices.