Ok, you are installing that new software whether purchased, freeware or trailware and many times you get more than what you were looking for. I am not talking about a virus, spyware, adware or anything malicious. The computer world calls that malware but I am talking about the extra 'stuff' that tags-along... some call it advertising but I call it a hitchhiking. Wikipedia defines "Hitchhiking (also known as thumbing, hitching, autostop or thumbing up a ride) is a means of transportation that is gained by asking people, usually strangers, for a ride...".
I will use the toolbar as an example. A necessary toolbar is that provided by Roboform. Roboform is a password manager which is made easier to use with the assistance of the browser toolbar. I still customize it so I don't waste screen space but the remaining buttons help me use the product faster.
An unnecessary toolbar is that customised (Google, Yahoo, MSN, etc) toolbar installed with some other applications. Typically it might be branded with their logo but has maybe a single link to open their software. The other buttons are standard links to your webmail, search, pictures. Sometimes they have popup blockers, site authentication, adware/spyware, weather and traffic notifications. I subscribe to a simple edict - if it helps with business use it otherwise loose it. Many of the functions of these toolbars already have been incorporated into the Internet Explorer such as tabs, popup blockers, phishing filter etc. The point is NOT that I am single minded Microsoft but it is supported by all the carrier and business sites. If you have a problem with a carrier or business site, trying disabling or removing the toolbar. I have seen some user workstations with IE8 + Roboform + Google Toolbar + Yahoo + MyCoupons. I wonder how anything could work. This user needed Yahoo to get to their personal webmail and favorites and did not want to miss the daily specials from MyCoupons. Oh, by the way, he also had traffic.com and weather.com running in the system tray! Done with my RANT for the day but I hope you understand why I caution about Hitchhikers. Click here for Toolbar Madness.
So when you open your browser does it look anything Toolbar Madness? Do you have new desktop shortcuts causing you to ask where it came from. I am going to give a developer a break here and say sometimes the extras are include with an installation as marketing or advertising. They need to do this often so they can obtain revenue so they can continue developing freeware or trailware. Advertising revenue is the Google or Yahoo Toolbar. 
I use and recommend a great product by Piriform called CCleaner. During installation you see their Logo, accept the License Agreement, select the default install location and INSTALLATION OPTIONS. The inattentive clicks rapidly through these and bam, you got the Yahoo Toolbar. With this products I unselect Add Desktop Shortcut, Add Run CCleaner in Recycle Bin, Add Open CCleaner in Recycle Bin but most importantly I don't want to Add CCleaner Yahoo Toolbar. Please read the installation screens carefully to avoid the Hitchhiker. Let me reiterate that CCleaner is a great product. The Yahoo Toolbar is useful to some but only when wanted. Don't trick me with it as a pre-selected option. I can accept an additional screen to advertise or recommend why the toolbar could be useful. Don't assume that it is wanted.
I use and recommend a great product by Piriform called CCleaner. During installation you see their Logo, accept the License Agreement, select the default install location and INSTALLATION OPTIONS. The inattentive clicks rapidly through these and bam, you got the Yahoo Toolbar. With this products I unselect Add Desktop Shortcut, Add Run CCleaner in Recycle Bin, Add Open CCleaner in Recycle Bin but most importantly I don't want to Add CCleaner Yahoo Toolbar. Please read the installation screens carefully to avoid the Hitchhiker. Let me reiterate that CCleaner is a great product. The Yahoo Toolbar is useful to some but only when wanted. Don't trick me with it as a pre-selected option. I can accept an additional screen to advertise or recommend why the toolbar could be useful. Don't assume that it is wanted.
