I've lost count how many times I've been given a computer to fix where the user is complaining of speed issues. "It used to be fast, when we first got it, but now it just crawls along. Do you think I need a new one?" is often the comment.
Upon booting up the slow and laggy machine, I often find many a tool installed designed to "optimise" and many toolbars installed on the explorer window - often so many that the browser window is barely visable.
Are these things a false economy?
In a word. Yes. But they have their place.
First rule is to make sure you KNOW what you are installing. There is countless SAFE software that you can install that will also install a tool bar onto your browser. IT SHOULD give you the option to NOT have this installed, but if it doesn't, then uninstall or disable to tool bar straight after. It's not really that necessary.
Everytime a tool bar is installed, in increases the running size of the browser window, and every tab you open after that multiplies the size, this will cause system drag on the memory. Ask yourself how many times you've used that toolbar, and ask yourself if you really need it, or so many of them.
Optimise programs are quite ok, but don't let them run in the background. Oddly, they'll SLOW your system down, because they have to run in the background to see if your systems running slow... called the "observer effect".
Run them once, get them to optimise your system, then uninstall them after. Keep your system clear of programs you don't use. Know what you install.