If you think your firefox browser is taking a bit longer time than normal, its time for switching the browser to compatibility mode. This is how it’s done:
Right click on your firefox icon and select the properties tab, where it says Compatability, check “Run this program in compatibility mode for” and select “Windows 2000” from the drop down menu.
Firefox loads faster on my laptop (Windows XP) after doing this, if it doesn’t work for you, you can easily revert by unchecking “Run this program in compatiblity mode for”. It’s worth giving it a shot.