The big problem of using Firefox is the waiting time when start up. Firefox take much time to start up compare with Internet Explorer, Opera, or Chrome Web Browser. Mozilla always promises that next version will have faster start up then previous version. But in my opinion the speed of start up is not increase significant. It is still loose compare with another browser. If you want to make your firefox run faster on start up then you can use Speedy Fox or by using Firefox Preloader.
Firefox Preloader is a utility that is designed to load parts of Mozilla Firefox into memory before it is used to improve the its start up time. It will increase Firefox startup on Windows computer.
The installation is not easy for end user. Fortunately the developer gives tutorial on Firefox Preloader addon website. Below the tutorial after you install the this add-on taken from Firefox Preloader web addon

- Open Windows Explorer and navigate to "C:\Program Files\Mozilla Firefox"
- Right click on "firefox.exe" and click on "Send To -> Desktop"
- Rename the just created desktop shortcut to "Firefox Preloader" (optional, of course)
- Right click on the shortcut and then on "Properties"
- On the Target field append " -preloader" so that it now looks like '"C:\Program Files\Mozilla Firefox\firefox.exe" -preloader' (see screenshot)
- Click "Ok" and you are done with the Properties window.
- Now drag the shortcut to your "Startup" folder (Windows's Start menu -> All Programs -> Startup)
- You're done. Firefox should now Preload at bootup, similar to what IE does...