Comment Re:Security... (Score 2, Informative) 344
Yes, but think about it this way. Lets say your computer runs at half its speed with an anti-virus.
I wouldn't run any AV that causes my computer run at "half its speed."
I used to be a huge Norton AV hater. But since v2009 they did a major overhaul to their AV engine and now it runs extremely well. 2009 and 2010 consume virtually NO detectable resources, update themselves literally every few minutes, and turn themselves off completely during gaming. Kaspersky 2010 is a bit worse performance-wise, but not terribly so. I've also installed MSE on a few PC's for people and have been impressed with its performance. None of these three slow your PC "by half" and of the three, I'd say Kaspersky is the biggest hog, but still far and away better than the Norton of old. AVG used to be lean and mean until v8 I think, then it bloated up and got slow too. Avira free was decent but the ads were too annoying, as was the mandatory annual registration renewal for it and Avast. I finally decided to pay, and have been quite satisfied.
So based on my experience, for free AV (that doesn't bug you with ads) I'd recommend MSE. If you're willing to pay, Norton 2010. And if you shop around online, you can get some good deals. I got 3 PC's w/ 2 year subscription of Norton Internet Security 2009 (and free upgrade to 2010) for $60, and I've actually found it even cheaper since.