Panda Cloud Antivirus Free is actually what I recommend for computer/laptop with low-end specs, since it's Cloud-based, there's hardly any heavy operations being effectued on the system that requires resources such as RAM or CPU. I prefer it to other good free Antivirus such as avast! or Avira, just because of it's really low resources consumptions.
..why Panda? It is relatively a new market anti-virus, untrusted yet. Or?
P.S. People are taking AVG, or avast!, or Bit Defender.
I dislike AVG since it tries to bundles foistware in the installation and pushes you to install their software even when the program is installed (AVG Web TuneUp). And when you uninstall it, it tries to make you install AVG PC TuneUp. It's really sad to see an Antivirus company behaving that way, real shame. Hence why you could say I'm almost "boycotting" their products. As for Bitdefender, they have to fix the buggy GUI and also the fact that most of the time it won't uninstall properly. Nothing to say against avast!, only the little annoying voice that can easily be disabled.