Does this sound familiar? You get a call from your parents. There's some problem with their computer. The printer isn't working, the computer won't connect to the wireless network or something like that. You go there and fix the problem, but while troubleshooting you also notice that there are some new toolbars in their web browser. When you ask them about the toolbars they usually say they have no idea how the toolbars got there.
These toolbars are typically bundled with other software and if you don't pay attention during the installation process, you might end up installing not only the program that you actually want, but also some toolbars or other software that you did not want at all. Why? The majority of the bundled software is opt-out - you have to explicitly say NO to the bundled software by unchecking some checkbox during the installation.
So, today I decided to start with a fresh installation of Windows Vista, then download the top 20 most popular downloads from Download.com, install them without opting out of the bundled software. This is how your Internet Explorer will look like:
Updated 2012-09-08: Fixed publication date. The post was published 2012, not 2010.