If you've been using the Internet for any length of time, you have probably come across websites where annoying pop-ups appear, or where either an offer or attempt is made to download some kind of program to your computer.

Now this may be "appear" to be some kind of helpful toolbar, or a desktop icon, or even just a URL to be added to the "favorites" in your web browser. Trouble is... how harmless are such programs? And... how many of these have you actually downloaded... without even knowing it?

The reality is, if you haven't performed one already, you're probably due for a comprehensive scan of your computer. Such a scan should go through every nook and cranny of your hard disk to find and remove any unwanted adware, spyware or malware - those programs that make certain ads appear on your browser or on your desktop, track your Internet usage, or, in the case of malware (i.e. malicious software) attempt to cause damage to your computer or steal your personal information and identity.

So how do you get your computer scanned for spyware, adware and malware? Fortunately, there are numerous software programs available to scan your computer for such software and, if you wish, permanently remove it from your hard disk. Many of these are available as free trial downloads, so you don't need to pay a cent to facilitate an initial scan of your computer.

Nonetheless, before you download the first spyware and adware scanning and removal program you come across, it's a good idea to find out a little about the various programs available.

Take a look at the spyware and adware scanning and removal programs on offer. Peruse their websites and consider their various features and benefits. Read through the various product reviews and comparisons to see what different people think of them. Then choose a couple of the free trial versions available to try out for yourself.

Download one at a time and perform a scan to see what it picks up. Then download another program and see what adware, spyware and malware this program is able to identify and remove.

Once you've tested two or three - or more - spyware and adware removal programs, you'll have an idea of the capacity of each, and which is likely to meet your needs. Of course, it is generally a good idea to purchase a full licence as some of the free trial versions do not come with automatic updates and other important features. However, in most cases, such licenses are in the $20-40 range and are therefore not particularly expensive... especially when you consider the damage they can prevent