For whatever reason, your system isn't working properly. Rather than trying to clean up the mess or hunt down some virus, my advise has always been to simply reformat the system. The specs above seem more than sufficient for this system to be running smoothly. Can you remember how fast this system was when it was new? Reformatting the entire CPU will eliminate any problems you may have. That's how I maintain my systems now. I store my data on an external HD, and at the slightest hint of a virus or spyware, I wipe it down clean and start all over. I don't even run a virus program because it bogs down my systems way too much. How to reformat a system is a whole other issue...
