By default, Mozilla Firefox loads slower than Internet Explorer as you launched it. You will need to wait for few seconds before you can start browsing the world wide web.
Here is a small program you can install in order to speed up the start up time when you launch Mozilla Firefox.
By installing Firefox PreloaderIt, it will load portions of Mozilla Firefox into memory first and keeps it their so that when you start it, it will load much faster in just one or two seconds time.
Besides, you can also configure Firefox Preloader to run at the Windows starts up so that you can double click and launch the Firefox browser instantly once you open up your computer every day.
Download: Firefox Preloader