Secure Computing: Free Virus Protection for Advanced Users with ClamWin
If you want an open-source anti-virus utility that lets you scan on demand instead of real-time, you may want to take a look at ClamWin, a utility based on the ClamAV scanning engine.
This lightweight application integrates with Explorer and even has a plugin for Outlook to scan email attachments. It does not offer real-time scanning, so it won't be for everyone and should probably be used by more advanced users.
Installing ClamWin
Installation of ClamWin is easy and straight forward. The only thing to verify is that the Microsoft Outlook component is checked if you are using Outlook.

You might want to include international help files if necessary, although there isn't a whole lot of choice there.
Using ClamWin
The ClamWin user interface is simple and basic. Unlike other utilities there is no flashy or fancy graphics, just select a drive and kick off the scan.
The ClamWin Preferences accessed from (Tools \ Preferences) is where the user controls how the utility operates. In this example I am setting the frequency and time of day ClamWin checks for virus database updates.
To schedule a scan click on the Scheduled Scans tab where you will notice there is nothing set up by default. You'll want to click the Add button on the right-hand side to create a new schedule.
The Scheduled Scan box opens and you can set the scan frequency (daily, workdays. weekly, or monthly), the time and which day of the week if you choose the weekly scan option. Here you will also browse to the specific folder to scan and then create a description.
ClamWin does integrate into Microsoft Outlook and when you launch Outlook you get a ClamWin splash screen as to verify it’s protecting.
After a few launches you'll probably find that screen annoying, but you can easily disable it in Email Scanning under preferences.
Updating the virus database can be done manually or scheduled as shown in the instructions above.
ClamWin is extremely light on system resources even during an active scan, unlike most anti-virus applications where you notice a lag in performance. You'll barely even notice it.
ClamWin saves reports for both database updates and scan reports. You can easily access the reports by selecting Tools \ Show Reports and select either report.
Conclusion
ClamWin is very light on system resources and does a great job, with plenty of settings available to tweak to your liking. There is a great reporting system and virus database updates are available sometimes multiple times a day.
If you are experienced and looking for a light weight and solid open source anti-virus utility you should check this out. We should note again that this isn't a great choice for inexperienced users since there is no real-time scanning.


One more thing might be said about ClamWin here: it's absolutely great for use with really old systems. Besides my Vista and XP computers (with Avira for antivirus) I still have a 1999 laptop running Windows98SE, with only 64Mb RAM. I still use it for some light internet surfing and mailing (to the surprise of some onlookers, Opera 9.5 runs very well on it). Most modern antivirus solutions either won't run at all on this legacy system, or they will slow it down to an unacceptable crawl. The only antivirus software that runs really fine with this oldie (that is, for regular system checks or checking new downloads directly from the right-click file menu) is ClamWin!
But keep in mind that it does not do on-the-fly scanning.
As a "workaround" I do download everything to the same folder and scan it from there - where also a scheduled scan is configured. To improve performance of the scan, I do move already scanned files away from there.
I have used ClamWin on my Portable Apps once and was wondering, does it just report virus's or does it actually try to clean and/or remove them? I couldn't tell.
@zeotter:
yes it will remove them or put them in a quarantine.
We tried the portable version at work to scan our thin clients and found it was very good at detecting nasties but it was very very slow, although possibly that was an issue with our thin clients. Overall the portable version is impressive considering that we were running it standalone from a flash drive. I do recommend the portable version.
I have tried AVG (slowed the system so badly that files started becoming corrupted); Avast! (quirky behavior by my monitor and Windows desktop); and AntiVir (system stalls and interference with some internet programs during startup). So, I thought I'd try Clamwin, since it doesn't have a realtime component. Unfortunately, Clamwin isn't recognized by Windows XP Security Center. I get the message that my system doesn't have any AntiVirus. Checked the Clamwin forum. The response there was that Clamwin is considered beta and therefore not recognized. It said to load an additional piece of software that Security Center would recognize. Oh well.
I really like this article, commandline tricks would be very usefull. Thank you.