This type of software is often installed without a user’s consent and often can’t be uninstalled without special tools. When distributors use tricks and deception to install uninvited software, trust is destroyed.

Your first line of defense is common sense. Be careful when you install new software. Only install software from trusted websites, and always read the license agreement. Some companies disclose that they install extra things with their software, but most people don’t read the license and never know it.

Before downloading any new software, look for guarantees that it’s spyware free. Even so, be on your guard - the file-sharing program Kazaa has been claiming to be spyware-free for years. Anyone who installs this software soon has an opportunity to test this claim.

How will you know if you’ve been infected by spyware? Some of the most common problems include unusual pop-up ads, a change to your homepage, new toolbars showing up in your browser and your computer acting strangely, such as freezing up or rebooting out of the blue.

If you do get infected with spyware, there are ways to get rid of it. A number of companies make software designed to get rid of it. These programs will scan your computer and check through their database of known spyware for any matches. These databases get updated frequently as new forms of spyware are found.

Some of these programs are free while others will cost. The paid versions sometimes have additional features, such as automatic scheduled scans. None of them are 100% foolproof however, so it’s a good idea to run more than one of them.

Some spyware is notoriously difficult to remove. They may make several alterations to your system settings and install files in different places. Often the only way to remove this type of spyware is to find the locations of all the files and manually delete them.

This is obviously not something you should undertake unless you’re quite familiar with Windows and working with system files. You wouldn’t want to delete something that renders Windows inoperable.

Once you’ve got rid of any spyware on your computer, you can help keep it clean by running a scan on a regular basis. Whether this is scheduled, or you do it manually is up to you.

Of course, you need to always be wary of anything you download. You never know when there is going to be a significant cost to that free software that looks so cool.