Symantic, the makers of Nortons, are one of the leaders in PC security.
Note: These products are not free, but then the best seldom is.
Although we at EasyNfree offer Low-Cost software and goodies, we try to offer quality and choice. If Security is a big issue with you, then maybe you should consider a "top-of-the-range" product. Like the Nortons Rage offers.
Visit Symantic's Web-Site for all the info.