My advice and that of others on the forum would be to uninstall BTNetprotect/McAfee or what ever it's called now. It can cause problems on some computers and is a resource hog. Do a search of the forum to see the problems. There are far better free antivirus programs available such as Avast Free and AVG Free.
If you do want to uninstall BTNetprotect use this guide and make sure you use the BTNetprotect/McAfee removal tool after you have restarted your computer.