Lifehacker: The Guide to Working Smarter, Faster, and Better, Third Edition

Hack 108: Firewall Your Windows PC

Level Medium

Platform Windows

Cost Free

A home PC connected directly to the Internet — especially with an always-on broadband connection such as cable or DSL — is a prime target for malicious software attacks. Predatory software constantly scans public networks (such as your ISP’s network) looking for insecure computers to attack, take over, and use for its own purposes. A criminal hacker can use an unsecured home PC to send out spam email, steal credit card or other identity information, or simply delete data or crash the machine for the fun of it.

A firewall can protect your computer against these types of attacks. Without a firewall, a PC connected directly to a cable modem is exposed to the wilds of the Internet — which runs rampant with infected PCs just waiting to spread their viruses and key-log your credit card numbers.

Does Your Computer Need a Firewall?

If you’re on a secure network — like at the office — or if your home computer is connected to a wireless router with a built-in firewall, it may already be protected. If not, running a software firewall can greatly reduce the chances of an outsider’s gaining access to your PC without your knowledge or consent.

Open ports on your computer represent possible entry points and vulnerabilities on your machine. Test out how secure your PC is by using a free online port scan application at www.t1shopper.com/tools/port-scanner/. If your machine has open ports, run a firewall to explicitly allow ...