If you have ever researched free anti-virus tools, you have probably come across an open source application called ClamWin which is built on top of the ClamAV engine. One big feature that ClamWin lacks, however, is it does not have ‘active’ scanning protection. Simply put, files are not automatically scanned when they are opened, you have to manually scan it. This ‘detriment’ has it’s benefits though.

Because ClamWin doesn’t offer active protection, it has virtually zero impact on system performance. Since the overhead implemented by active scanners can be significant (think about it, each time you open a file it has to be scanned first) it can really knock down your system performance. Additionally, you can typically only have a single active scanner on a system (for obvious reasons), but as many passive scanners as you like.

Now, the reason ClamWin is a great compliment to your existing AV program is because it is a passive scanner it can run next to your existing utility with no impact on it. This gives you the ability to use its scanning engine to perform full system scans to ‘double-check’ you system. Additionally, ClamWin is open source which means it is complete free for personal and commercial use.

Say or believe what you want about the effectiveness of its scanning engine, but two sets of eyes are better than one. You can configure ClamWin to attempt to clean infected files or simply have it report on and automatically email virus detections. Anyway you slice it, having ClamWin as a secondary AV tool is a great way to add protection with minimal impact on performance.