It's impossible to make a single program that it is able to control all of these variables. On the other hand, if you insert the words how to know spy on your computer in your favorite search engine, it's quite likely that you won't find useful information.

That's why the responsibility is in your shoulders. And the first thing that you need to do is to update your OS. Believe it or not, there are thousands of people in the world who don't update their operating system; because of this, their private information is in peril.

Another important thing to do is to have a software firewall installed. There are several companies, like Symantec or Zone Labs, who sell firewalls for the consumer market. They are easy to use and relatively cheap. Fortunately, they have trial versions so you can test them first. In case you are using Windows XP and do not want to spend any money, you can use the firewall that is included with the Service Pack 2.

The antivirus is another basic tool for fighting spies. Although they won't be able to find the spy, they will be able to detect any surprises left behind by them. You don't want to be the sudden victim of the latest version of any virus, so assure yourself by installing a real time antivirus that is aware of everything that occurs in your PC.

As in the case of firewalls, there are several companies that make antivirus for the consumer market and at affordable prices. Go to Download.com and use the trial versions in order to choose the one that adjusts better to your needs. If you are short in cash, then use the AVG Free Antivirus. It's quite basic but it is a very good program.

Finally, there are anti-spyware programs. One of the most known packages is Ad-Aware, made by Lavasoft. There is a free version with limited capacity and a full version that has all that you need for protecting yourself from spying software.

The conclusion is that you don't have to become a computer geek in order to become free; computer spy programs will always exist, so assume your new responsibility as a PC user. Like it or not you will have to learn how to perform maintenance to your computer in order to keep your private information safe. And that means that you need to maintain yourself updated. Remember, computer spy software is getting better and better. Do not overestimate it.