Panda Security uses a security platform called 'Collective Intelligence' for ‘Cloud Antivirus’ which offers high-level protection in real time, and considerably reduces the system resources.
It is the lightest and fastest antivirus program. According to Panda Security, because of the cloud-scanning from PandaLabs’ servers, the detection rate is very high.
If you have any of the previous versions installed (Beta1, Beta2 or Beta3) do the following:
Panda Cloud Antivirus supports Windows7, Vista and XP.[via]