Download Avira Free Anti Virus
The free version of Avira AntiVirus is easy to use and one of the most reliable virus protection services.
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 real time monitoring. 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. Knowledge Base with virus descriptions on web site. Rootkit Detection and Removal.
Note that Avira does not protect against spam mail. Here is how I defeated spammers once and for all!