Securing your Computer without Slowing it Down

Security for your PC is important, but over securing will slow it down. 
One such case is went two antivirus programs attempt to run on the same PC. If you have McAfee AV and Norton AV (or any other brand) both installed, pick one and remove the other. The behavior of any antivirus program is to take control of your system. It needs to for the purposes of protecting your important stuff. But when two antivirus programs assume control, it's like two kids fighting in a sandbox. Neither one does much good and the performance of your PC will suffer. One antivirus program could have been part of a free offer and it was installed. Hoping that one day you will sign up for a paid subscription. So it could happen that two antivirus programs are running without you being aware of it. 
Remove one and your system will run much faster and efficiently.