I just added mozilla to the HKLM/software/microsoft/windows/currentversion/run

I added a new string value, and called it Firefox. Then I modified the new value.
I used the following:
C:\Program Files\Mozilla Firefox\firefox.exe

Now when I start my PC, mozilla loads automatically, I don't have to hit the firefox icon in the quick launch. But there is no firefox icon in the sys tray.

But now when I close firefox it opens instantly. Very nice.