It depends on who you ask, I'd say Microsofts Security essentials as it doesn't come with all the bloat the others do or if you don't mind a one off £15 or £20 fee Malwarebytes paid for is pretty good. Always keep your computer up to date with the operating system updates as well as Adobe Flash/Reader and Java - these three are the top attack vectors for most OS's.
Yeah thats my set up on both comps but you have to have gen copy of windows before MSE works!
TBF since this set up I have zero issues anymore Malwarebytes Pro kicks arse and both are the lowest resource hugging stuff around which makes my old systems work like a dream!!!
