Avira AntiVir Personal - Free Antivirus is a comprehensive, easy to use  antivirus program, designed to offer reliable free of charge virus  protection to home-users only.  
Avira offers:
 - Extensive Malware Recognition of viruses, Trojans, backdoor programs, worms, etc.
- Automatic incremental updates of antivirus signatures, engine and entire software.
- Permanent virus protection, with Virus Guard real time monitoring.
- Install and configuration in just a couple of steps, setup to protect your PC in minutes.
- Virus protection against known and unknown threats, using an advanced heuristic system.
- Scheduler where you can set the scanner to make automatic virus scans or updates on your system.
- Forum and phone support, Knowledge Base with virus descriptions available on web site.
- VistaSupport.
- Rootkit Detection and Removal.
  It constantly and rapidly scans your computer for malicious programs  (such as viruses, Trojans, backdoor programs, hoaxes, worms, dialers  etc.), monitoring every action executed by the user or by the 
operatingsystem and being able to react promptly when a malicious program is detected.  Actions include repair, delete, block, rename and quarantine programs or  files.   This application also features enhanced protection against unknown  boot-sector viruses, issuing alerts for boot sectors suspicious formats.  Through the permanent update of the detection engine, the protection is  ensured constantly: the user can set the product to download any  updates when available, thus keeping you clean and safe