PC Security

As I'm often asked for advice on PC security for Windows machines, here is a brief summary of the free and opensource tools available for Windows users.

Windows
Windows itself has its own important defences. Make sure that your auto-update is turned on. Out-of-date system software is going to be more vulnerable to attack.

Windows Defender http://www.microsoft.com/windows/products/winfamily/defender/default.mspx

"Windows Defender is software that helps protect your computer against pop-ups, slow performance, and security threats caused by spyware and other unwanted software by detecting and removing known spyware from your computer. Windows Defender features Real-Time Protection, a monitoring system that recommends actions against spyware when it's detected, minimizes interruptions, and helps you stay productive."

Anti-Virus Software
There are a number of basic free anti-virus software options.
AVG http://free.avg.com/

"Antivirus and antispyware protection for Windows available to download for free. LinkScanner Active Surf-Shield checks web pages for threats at the only time that matters – when you’re about to click that link. AVG Anti-Virus Free Edition. Award-winning antivirus and antispyware. Real-time safe internet surfing and searching. Quality proven by 80 million of users. Easy to download, install and use. Protection against viruses and spyware. Compatible with Windows 7, Windows Vista and Windows XP. AVG Anti-Virus Free Edition download and installation is only available for single computer use for home and non commercial use."

ClamAV http://www.clamwin.com

"ClamWin is a Free Antivirus program for Microsoft Windows 98/Me/2000/XP/2003 and Vista. ClamWin Free Antivirus comes with an easy installer and open source code. You may download and use it absolutely free of charge. It features: High detection rates for viruses and spyware; Scanning Scheduler; Automatic downloads of regularly updated Virus Database. Standalone virus scanner and right-click menu integration to Microsoft Windows Explorer; Addin to Microsoft Outlook to remove virus-infected attachments automatically."

Confickr Eyechart http://www.confickerworkinggroup.org/infection_test/cfeyechart.html

"Conficker (aka Downadup, Kido) is known to block access to over 100 anti-virus and security websites. If you are blocked from loading the remote images in the first row of the top table above (AV/security sites) but not blocked from loading the remote images in the second row (websites of alternative operating systems) then your Windows PC may be infected by Conficker (or some other malicious software). If you can see all six images in both rows of the top table, you are either not infected by Conficker, or you may be using a proxy server, in which case you will not be able to use this test to make an accurate determination, since Conficker will be unable to block you from viewing the AV/security sites."