Working on your laptop at the local coffee shop is becoming all too common a scene nowadays.

While many of these cafes now offer free Wi-Fi, what you might not know is that there are security issues that affect your laptop as much as your own personal home.

Here's the deal: Unless you want a hacker to read your personal e-mail or even browse around in your files, you need to set up security measures to protect them. Think of it as similar to closing and locking the doors to your home.

At home, believe it or not, the story is the same. A stranger can actually drive by and surf your Wi-Fi from the street if you don't have security measures in place, unbeknownst to you. A neighbor in your high-rise condo could do the same.

While most Wi-Fi moochers simply want to check their e-mail or browse the Web, an experienced hacker could access your computer's documents and photos, as long as they're shared files, even spy on your Skype conversations.

A malicious hacker could even plant a virus in your laptop, putting in a beacon that he or she can use to hijack your computer.

It happens more often than you think.

Troy Nichols, senior networking and data security expert for SuperGeeks, says hackers can easily access shared files, and most Microsoft Windows programs turn on file sharing by default.

Nichols shares the following advice and tips on keeping your Wi-Fi secure:

» Set your wireless router to secured mode. Most users buy a router from the store, take it out of the box and plug it in, following a few easy steps to set it up. You want to configure it to a secure mode with a password, which will take a few extra steps. When hopping on to Wi-Fi, look for a little padlock sign.

If you're not sure how to do this, call in a professional.

“;If you close that first door by not having your wireless fully open like that, you close the main door,”; said Nichols.

» Keep up with updates. But don't forget about the side door and back doors.

Make sure you have the proper anti-virus software installed on your computer, which will warn you of the presence of one at an unprotected, public Wi-Fi source.

Also, when your computer software—whether it be Microsoft or Apple—pops up to ask whether you'd like to install an updated version, click yes instead of later. Many users oftentimes ignore these very programs that are designed to protect their computer from glitches and security holes, but they are important.

“;Essentially, you've closed one door but left the other wide open,”; said Nichols.

Some red flags that your computer has a virus include symptoms of sluggishness, unresponsiveness and a propensity toward crashing. Also, your Internet provider might send you a letter in the mail informing you that there has been suspicious activity.

» Join networks that you trust. Whether it's at home, a cafe or the city's municipal Wi-Fi, know the network. Some cafes require users to buy coffee and then get a password, while others just leave the network open.

A fake, open Wi-Fi address—called a “;honeypot”;—is sometimes planted by a hacker to get into your system. These hackers are on the lookout for unsuspecting victims doing online banking or shopping with their credit cards.

Never, ever, do banking or enter your credit card or confidential information on an open wireless system.