You, my friend, have a SMITFRAUD infection! Congratulations, it's one of the most painful and frustrating things to remove short of a wipe and reload. AVSystemCare is one of many similar products that scare you with aggressive adverts, pop-ups and other assorted nasties to goad you into buying their useless product. You have an infection, and your AVSystemCare is most likely the culprit- definitely not the cure.
There are some tools you can try, Smitrem and Roguescanfix. Google them. Good luck, because they can get nasty.
Also, get Norton off your system with SymNRT. Norton was once good, back in 2002-ish...now, they must funnel all their money into marketing because their latest offerings are bunk, and not for low-end systems. Norton WILL suck your system dry. And it will miss a lot. As a mobile computer tech, I'd say about 30-40% of my calls end up being related to Norton.
Spy Sweeper with Anti-virus is great right now. But it's always changing.
Do yourself a favor and ditch that bs.