There is an organisation called AV-Comparatives that tests antivirus programs and compares their performance. They’re independent from the antivirus vendors making their tests more useful. So it’s good to look through the results and see which antivirus programs are working better than others. Below are their top 7 programs, in no specific order:
Full details of their tests are here – click on the August 2009 report. I was surprised to see Trend Micro was missing from the tests. I tried contacting them about it but I haven’t received a response.
So when you’re ready to invest in a good antivirus program for your PC you can use the results of their tests to base your decision.
Also keep in mind there are fake antivirus programs out there, they pretend to do a scan but actually install malware.