Firefox is a notorious slow starter (it used to take mine 10-15 seconds) as unlike IE it is not an integral part of the OS so it is already partially loaded. Firefox has to load completely from scratch and opens in excess of 50 files exe, dll, .js, extensions, etc. so these have to be checked if you have your sensitivity set to high they will all be scanned. Life is about compromises, security V performance in this case.
Word (97) for me opens in 3-4 seconds.
However, speed is subjective and depends on your avast settings, system performance (cpu, ram), HDD fragmentation, etc.
