Arjun said:Avira is lighter than avast & has better detection.
Rockfella said:Avira is not lighter than Avast, takes a lot of updates but has better detection than Avast. I've been using avast without problems, tried Avira which slightly slowed down my PC, diff might be greater in a laptop. Both are freewares (home editions) U try both, use what u feel... after all good browsing habits is key to remain virus free not the AV!
MSE has been know to slow down systems, check the reviews.zenflox said:MSE (microsoft security essentials)..
blows all AV products out there. Reading reviews will help you make up your mind