pparks1 said:
The other hit that computers take from installing software is that with quite a number of free utilities out there, they also come bundled with other things that you might not be aware of. Some things seem simple, like browser tools bars and such. However, as more and more of these small little extra things get loaded, they launch automatically and integrate themselves with other applications so now each time you launch something like IE..you not only get IE..but all of it's associated tool bars and such.

I pay very close attention to the installs that I perform on my machine. I often do them custom and turn off anything extra that I don't need. Some free apps, don't give you a choice to NOT INSTALL the additional component...but they do put an entry in the Add/Remove programs list where you can remove the component. I believe this happens with Fox It Reader for PDF's...which installs a toolbar...which I then promptly uninstall.

Another reason to that computers slow down can be from improper or incomplete installs. And I believe that often times utilities and such which are designed to improve the performance of your machine can be the result of some of these broken items. Then, your computer might try to access something and it may try searching for 20 seconds before it quits and just gives up. These things cost you in time and performance.
I am the same in that generally when i install something I do custom installs. Its not the first time i have seen something ticked like "install google toobar" or "ask toolbar", or yahoo or something like that. I don't like getting extra on my machine I don't want.