First I want to start with some simple thing to keep your computer safe and sound while browsing the web and then I will suggest some things to keep all of you data safe.   Most of this information pertains to Windows XP since I believe that is what most people are using.

Windows has a built-in firewall, but I wouldn’t rely on it. It hides you on the Internet. That means you’re protected from incoming transmissions. But if you get malware on your machine, the Windows firewall won’t help you. It doesn’t block outgoing transmissions. The ones listed below are free and do a good job of blocking unwanted traffic in both directions.

Comondo Firewall Pro http://www.personalfirewall.comodo.com/download_firewall.html

ZoneAlarm http://www.zonealarm.com/store/content/company/products/znalm/freeDownload.jsp

Ashampoo http://www.download.com/Ashampoo-FireWall/3000-10435_4-10575187.html

Antivirus software is essential. Although a firewall is the first line of defense, a few bad eggs inevitably make it through. That’s when a good antivirus program saves the day.

Antivirus programs need frequent updates to be able to identify the latest threats. Most programs require paid subscriptions for these updates. But you can still find some that offer free updates.

AVG Anti-Virus http://free.grisoft.com/doc/downloads-products/us/frt/0?prd=aff

Avast Anti-Virus http://www.download.com/Avast-Home-Edition/3000-2239_4-10019223.html?part=dl-AvastHome&subj=dl&tag=button&cdlpid=10019223

Avira http://www.download.com/Avira-AntiVir-PersonalEdition-Classic/3000-2239_4-10322935.html?part=dl-10322935&subj=dl&tag=button

Along with firewall and antivirus programs, anti-spyware is a security must-have. Spyware is a particularly unpredictable type of threat. It can trigger pop-ups or cause your computer to slow to a crawl.

Even worse, spyware can work in the background without noticeable symptoms. You should use a few anti-spyware programs to ensure that each possible threat is detected.

Spybot Search & Destroy http://www.download.com/Spybot-Search-Destroy/3000-8022_4-10122137.html?tag=lst-1

AVG Anti-Spyware http://free.grisoft.com/doc/5390/us/frt/0?prd=asf

SpywareBlaster http://www.javacoolsoftware.com/spywareblaster.html

SpywareBlaster is an effective anti-spyware tool. Unlike most anti-spyware programs, it does not scan the hard drive for spyware. Its strategy instead is to prevent modifications of your files and settings. For example, it can block browser toolbars from installing themselves.

SpywareBlaster can be used to prevent changes to Windows’ HOSTS file. It also has a System Snapshot feature similar to Windows’ System Restore. SpywareBlaster will report any changes to your system since the last snapshot.

Now that we have the basics covered lets go a step further.  There are a lot of things that need to be updated on a PC besides the normal things like your Anti-Virus, Anti-Spyware, and Windows itself.   Many other programs need to be updated because of Security Problems.

Windows  Update http://update.microsoft.com/microsoftupdate/v6/default.aspx?ln=en-us  (You will need to use IE)

Microsoft Office Update http://office.microsoft.com/en-us/downloads/maincatalog.aspx   (You will need to use IE)

Next is a great program Secunia that will check for a lot of other programs that need to be updated like RealPlayer, iTunes, Flash Player, Java and many more.    Just click on the Start Now Button.         http://secunia.com/software_inspector/

Any old versions of Java found can be removed in the Add Remove Program section of Control Pane.
If you use a combination of all of these Programs your PC will be fairly safe but nothing is 100%.   That is why I suggest that everyone who has any data on their PC that they would hate to loose, and that is all of us, do the following.    Go out and buy an External USB 2.0 Hard Drive with a capacity of somewhere between 120 and 500 gig.   Also buy a copy of a program called Norton Ghost, any version from 9 on up will work with Windows XP.  Norton Ghost will make an exact duplicate of your Hard Drive.   If your Hard Drive dies (all of them will sooner or later) or you get a virus, spyware, or delete an important document by mistake you can simply boot from the Ghost CD and restore your PC exactly as it was when you did the backup.   No reinstalling Windows, all of your programs and having all of your data gone forever.

Now it is important to do regular backups, I suggest weekly since it will only take about 30 minutes and most of it takes place with no user input, so you can start it and walk away.  This has saved my butt more than once!

If you follow these tip you will be relatively safe but as I said before nothing is 100% so make sure and do those backups to protect your data!