The Free Software Files

I’ve been happily using the free version of AVG Antivirus for a number of years. However, I’ve become increasingly concerned about the amount of memory it uses and about how slow it makes my PC run when performing on-access scanning. Recently my current installation started bombarding me with pop-up windows informing me that it was time to upgrade so I visited the AVG web site to check out what the latest version had to offer. In addition to the standard antivirus protection I noticed that anti-spyware and something called Safe Search have been added. Mmm, I thought, that will push up the amount of memory and processing required to an even more unacceptable level. Time to find an alternative antivirus application.

Enter ClamWin!

Clamwin is a free and open source antivirus appliction for Windows based on ClamAV, which is an antivirus program for UNIX.

The first thing you need to know about ClamWin is that it does not feature on-access scanning of files, i.e. real-time protection – at least not yet. Some may see this as a problem but if you’re careful it need not be.

In my experience as an IT professional most virus infections result from opening files that, on reflection, you’d never have touched with a barge pole normally. So if you take the time to pause for a moment before opening that email attachment or file you downloaded from the interweb you will dramatically reduce the likelihood of your PC becoming infected. If you couple this care and attention with frequently scheduled ClamWin scans of those parts of a Windows installation most likely to be infected by a virus (the Windows directory itself and the Documents & Settings folders) you reduce the chance of infection to more or less zero. Of course you also have to be sure to scan all other areas of your system regularly too, as well as making sure that you keep your antivirus definition database up to date (ClamWin very thoughtfully does this for you). All too often I’ve found myself removing viruses from PCs where the virus definitions were 6 months or more out-of-date!

Anyway, to the ClamWin program itself…

Once installed ClamWin runs as system tray entry which has a very small memory footprint. This tray entry allows you to configure ClamWin and to open the main ClamWin interface, manually download updates, view scan and update reports, schedule virus scans, check for version updates and visit the ClamWin web site. In addition to this the program adds a Scan with ClamWin Free Antivirus extension to the right-click menu within Windows Explorer. This is very useful as it allows you to invoke a manual scan of any suspicious files before you open them. Whilst this is perhaps not as elegant as a real-time scan it certainly uses less memory and makes your PC run more efficiently.

I recommend that you set up a schedule of virus scans that will process the Windows directory and the Documents & Settings folders once a day, and a full system scan at least once a week. Though I should stress that that is what works for me – you may need to schedule more scans depending on how you use your system.

You can also instruct ClamWin to scan email attachements (both incoming and outgoing). It can be configured to exclude file types that you specify from scans and you can also limit the size of files that will be scanned (e.g. by telling the program not to scan files that are larger than, say, 100Mb). There is also an option to adjust the priority assigned to virus scans and to send an email alert if a virus is detected. All of which makes ClamWin a pretty powerful package despite the lack of a price tag.

As a result of moving to ClamWin, I have noticed an improvement in the performance of my PC – applications load and run faster now that they are not being scanned each time they are accessed – and I’m also experiencing quicker boot times. And even when ClamWin is conducting a scan in the background there is no noticeable impact on the performance of my PC.

The ClamWin site indicates that they are working on an on-access component which will be available in a later version but I now wonder whether I’ll find that feature necessary at all. That said, there are many others who would prefer that an on-access scanner be included, or at least that they have the option to turn one on/off as requirements dictate. That’s why the current incarnation of ClamWin falls slightly short of a perfect score. However, it remains an antivirus program with a very bright future.

Final Score: 4 out of 5