Several years ago I learned a simple trick from one of my computer repair clients who was a security consultant and college professor. They would turn off their wireless router for their office when they were done with the internet on their computers. This way no outside intruders or malware could invade any of their computers. They could still work locally on word processors, spreadsheets and other programs. Then when they needed the internet, the wireless router was powered back on and away they went surfing and reading their email. I started doing this for my office and it does keep outside intruders out when network devices are off. Even when the computers in the office are still on and running.
But this isn’t an excuse for not using security software or common sense. Windows computers still need a security product installed like Comodo Internet Security. So give this a try and let me know what you think.