There is plenty you can do to speed up Firefox. I found this tutorial on a Linux site, but the tweaks are relevant to the browser not to the OS so go ahead and use them in Windows as well.
http://www.ubuntugeek.com/speed-up-f...b-browser.html
The tutorial is written, not in video format but it is much more detailed with many more methods of optimising Firefox for speed and efficiency. I have implemented all of them and the difference is incredible.