You could have a Windows PC, a Mac, or even a Linux computer. The fact is no one is immune to malware, the blanket term for all the evil software out there waiting to attack you. Did you know that miscreants using malware can steal your identity, bombard you with endless advertising, "hijack" your browser leaving you stuck forever on one website, or lock down your files until you ransom them back for cash?

Worst of all, they can turn your computer into a zombie that may appear to function normally. Unbeknownst to you, your computer will send malignant spam messages to thousands or millions of other computers, trying to turn them into zombies as well.

All that sounds pretty awful, and it is. But there are simple precautions you can take that, will go a long way toward eliminating the danger from malware. These 6 steps to lock down your computer come from Neal O'Farrell, founder of the Identity Theft Council, and an advisor to governments and businesses. You can find a lot more information in the handbook Think Security First!, available free from the council in partnership with Credit Sesame.

1. Install antivirus and anti-spyware software on every computer you use.

There are excellent free choices out there for protection, such as Malware Bytes and AVG. Make sure you have protection both against viruses and against spyware--software that some websites will sneak on to your computer's hard drive to allow it to track what you do as well as force unwanted advertising or websites on you.

Set your antivirus software to update every 24 hours, and either set your anti-spyware to update automatically as well, or make sure to update it yourself and perform a sweep of your computer on a regular basis, ideally once a week.

2. Make sure you have a firewall that can block outbound traffic.

A good firewall is the third piece of your security puzzle, along with antivirus and anti-spyware protections. A firewall is what it sounds like, a digital wall around your computer that keeps intruders at bay. It should alert you every time an external piece of software accesses your computer, but also when an application on your computer accesses the Web. The reason you want to be sure it monitors and can block outbound traffic as well is that this can prevent your personal information such as passwords being sent off to the hackers.

3. Only download or install software from sources you completely trust.

This goes not only for executable software such as programs and games, but also seemingly innocuous items such as mortgage calculators, screen savers, and even video clips, all of which can hide malicious software. Only download software from websites you know you can trust or from

When searching online for software to download from an official site, be careful of the top few results which may be sponsored results (they'll be identified that way, although perhaps in tiny type). This could lead you to mistakenly download a piece of software from a third-party site, which also wants to install a bunch of other stuff. Don't go there.

4. Browse carefully.

An estimated 9,000 new infected or vulnerable websites are discovered every day, according to O'Farrell. So it's smart to be very conservative about the sites you visit and links you click. Simply opening the wrong web page can lead to malware getting downloaded to your hard drive, and that can cause you a ton of grief.

Stay away from websites that offer free porn, opportunities to make lots of money, and other such temptations. You may also want to consider installing safe browsing software that reviews sites for known security issues before opening them.

Be particularly wary when unwanted pop-up windows appear with advertising in them or other annoyances. Close them by clicking Alt + F4 (in Windows), rather than clicking on the x. Some pop-ups secretly install spyware on your computer and closing the pop-up this way can stop that from happening.

5. Install attentively.

O'Farrell counsels reading the fine print in terms of service or licensing agreements before you install. Admittedly, these documents can run to hundreds of pages of legalese, so that may be a tall order. But do be very careful as you install a new piece of software to pay attention to what you're agreeing to. Many companies--even large and very reputable tech companies--will routinely ask permission to install extra software, change your home page or preferred search engine, or otherwise alter your online experience. If you click "accept" through the installation process without paying close attention to what it is you're accepting, you may be unhappy with the results.

6. Keep up with patches and anti-malware updates.

It can be tempting to put off patches and software updates till later when you have time for them, but you're running a risk if you do. Malware creators know that as soon as they release their bad products into the wild, security companies and software vendors will start racing to block or eliminate them. Their best hope of doing the most damage is to get onto as many unprotected computers as they can as quickly as they can. Don't let yours be one of their victims.