AVG Anti-Virus Free 7.1.394a752
Just being updated AVG Free Edition – Free for Home users. AVG Anti-Virus offers maximum virus protection, product customization, and free virus database updates and technical support. The core of the testing engine is a Virtual Device Driver which loads into memory on Windows startup.
Also as an alternative you can use avast! home edition, which is also freeware. AVast! is an antivirus set that is able to detect the presence of viruses in computers. It has a powerful antivirus kernal that has a boot-time scan, improved resident protection, heuristic analysis for email, and a script blocker. The program works great as a on-demand and/or resident virus scanner. The skinable interface is easy to use for any user.