oahazmatt writes "Some time ago my wife was having severe issues on her laptop. (A Dell Inspiron, if that helps.) I eventually found the cause to be McAfee, which took about an hour to remove fully. I installed AVG on her system to replace McAfee, but we have since found that AVG is causing problems with her laptop's connection to our wireless network. She's not thrilled about a wired connection as the router is on the other end of the house. We're looking for some good, open-source or free personal editions of anti-virus software. So, who on Slashdot trusts what?" When school required a Windows laptop, I used Clam AV, and the machine seemed to do as well as most classmates'. What have you found that works?