I never have any problems except when Alex or JL are having fun...
My PC is loaded with layers of security although it would probably easier to set up initially if I just used sandboxing. There is the hardware firewall in the router, Online Armor software firewall with HIPS, Avast AV, Prevx AS, odd scanners, plus secure browsers and email client (not IE or Outlook Express).
Everything is updated and purged. Use JavaRa. Do not use risky stuff like Windows Messenger or Adobe Air. Take a new hard disk image when your PC is new, copy that and add an incremental image with your apps, export all data and wipe your disk every six months and reinstall the image. Update all and you have a new clean PC.
Don't ever allow teenage kids on your PC
