yah, get Ad-Ware, Spy Sweeper, and McAfee VirusScan Professional. (good for constant check ups on e-mail, downloads, etc. Monitors all incoming files.) (try to get for free)
Thats what i use. If you had this at the time of the pr0n incedent, so many messages of incoming viruses wouldve scared the freak kid away.
Thats my opinion. Of course, there is jaarsdi's idea, the best one.
PS: I never get logged out...
PPS: oh, and maybe try to get a nice firewall. I dont have one but i hear they are good to have.