Most of our tips focus on specifically thwarting laptop theft and loss. But here’s another one that’s related to data theft but not hardware-related.

It’s crucial to use an updated, current, industrial-grade firewall on your computer. Windows, for example, has one built in, but products from Symantec, McAfee, and others can also extend the functionality.

A firewall can be used to do a number of advanced things but the main idea is simple: it’s a shield. It’s a wall. It exists to prevent outside intruders (“fire”) from coming in. You might be amazed at how frequently remote attempts are made to hack into your PC over the Internet.

Even if your PC is behind a network firewall device (such as a corporate or home router), be careful, because laptop users are notorious for picking up and leaving that safe environment and forgetting that their computers are wide open when connected to the local Starbucks’ WiFi network.

Be sure to turn on and properly configure your operating system’s built-in firewall, so that it only allows inbound connections for services you need, and blocks all others. Or, get a commercial product to extend the security and functionality.