maggioneato,
It sure sounds like your comp is full of pests. The link BOAC gave you is a good start.
Take Care,
Richard
P.S. If your surfing of the net is so slow now, I would also look to see if you are infected with a virus that launches DoS Attacks from infected computers. (You might be launching DoS Attacks and not even know it. You can tell very quickly by checking your outbound traffic with ZA.)