NONSENSEWhy IE loads faster:The internet explorer application itself is very small with most of the work being done by the supporting DLL's. These are loaded at bootup, not to speed a launch of IE, but because they are used by the system itself.Prefetch switch:The switch /prefetch:1 does nothing for Firefox. This switch is used in auto-generated shortcuts to Windows Media Player, but not for what you think. I will leave the description to Ryan Myers, member of Microsoft's client performance team:

Http://blogs.Msdn.Com/ryanmy/archive/2005/05/25/421882.Aspx

-reply by Larry Miller

I am no expert, but I do know that Firefox was taking literally about five minutes (!) to load on my XP computer. (No other programs take such an abnormally long time). I added the prefetch switch, and now it takes less than ten seconds.  As such, I believe that you may be mistaken in your opinion that it doesn't help.

Firefox used to be good but with every new version it gets slower to load. I regularly have to go into Task Manager and end the firefox process to get it to run... Sadly it's becoming old news. Opera seems to be a better bet!

I hate IE and that is why I changed to FireFox. However, after Google released Chrome, I have been using it ever since. Chrome takes literally 2 seconds to open up and loads pages faster than FireFox or IE. Other advantages are it's clean interface, AJAX technology, and many more. Ofcourse, Chrome is still young and needs more features that are present in FireFox but it has lots of potential. The most annoying thing I find about it is that some sites's applications only work on IE or FireFox (I.E. ESPN 360, TurboTax, etc.). Other than that, I would highly recommend Chrome especially after they get out of 2.0 BETA.

That's what fixed the insanely slow startup time for me. Go to Tools/Options/Advanced/Update and turn off update checking. Now FF loads quickly. You'll have to remember to manually check for updates though, under the Help menu.

Firefox takes less than a second to open if you have Firefox preloader installed, I think the issue is that it can take around a minute to open-up initailly right after startup.

I don't know how people are getting such long startup times for Firefox, since I don't presume to know what you're running.  But I can attest that for the life of me, Firefox has never taken more than a few seconds to start up, and I've been using it since pre v1.0.Perhaps reiterating some obvious points that I use, and a rough description of my setup can be helpful...First off:To the guy with a lot of fonts... Having too many fonts installed will slow down your computer in general, not just firefox.About firefox taking "5 minutes" or any outlandish number to start:There are many reasons this can happen.  Common sense really, but can be easily overlooked.  * too many extensions and themes* too many simultaneous tabs as a homepage, * the homepages are themselves, heavy. (overuse of flash, web apps etc.)* installed a useless flash game* have many useless toolbars* have many plugins installed that are hardly of use* have issues with Java Runtime* have kids who've been using their computer with admin access to system directories, and a love for games.  * also, there are many who aren't aware that Windows loads its GUI before many of its services to make it (appear) to boot fast.  I've seen this happen many times.  The user will subsequently start Firefox before their computer is even done booting, and wonder why it takes so long to start up the browser.(The list goes on and on)Naturally, "too many" of anything depends on system hardware and configurations.  For a basis for comparison:I'm running Pentium 4 2ghz single core, 1.5 GB 400mhz DDR, double harddrive (1 for apps & OS, 1 for storage and pagefile), evga 7600GT with 512mb DDR2 AGP8x videocard, on Windows XP.  (old but not ancient, still kicking system).  I stayed away from Vista like the plague.  My ffox initial startup is a few seconds on average even after updates.  We're talking 2-4 seconds at the very MOST.I have one custom theme (not all themes are created equal; some are heavier and/or buggier than others), and a modest set of extensions that include only:Adblock PlusDownloadHelperEvernote WebClipperFoxyProxyNoScriptNote that Adblock Plus and NoScript may actually speed the appearance of load times since it blocks advertisements and various scripts from loading.  It can also make it appear to start up slower since some pages will go nuts if it can't load up a given advertisement; e.G. - it will never be "done" loading.  I have a custom theme, but installed 1 and only 1.  I refrain from using heavy add-ons like FoxTab, etc, since I don't have the computer to run it to my subjective standards.  I also use third party applications to make host file additions: these additions don't really do much for speed except reroute potential calls to known bad servers to instead, refer to my loopback address.Spybot Search & Destroy's "Immunity Settings", and SpywareBlaster.  In combination with Adblock Plus and NoScript, my web surfing experience is very sane (no ads, unintended flash popups, hijacks, clickjacks, etc).  Some people will say NoScript is very intrusive, which it arguably is, since by design it's a whitelist program, but well worth the trouble for me anyway.Finally, my home page is 1 tab: and it goes to google.Com... Very little to start with, & shorter start-up time as a result.  If I want to load a set of pages, I'll refer to one of my set of bookmarks and "open all in tabs" after the browser is started. At least my browser is started, with its homepage open, and I will know for certain, any issue I come across isn't an issue with the browser itself.  Having too many themes and extensions does a number of things:1) if fox is set that way, it will check for updates for (all) of them at its startup.2) after startup, it'll always have them loaded with firefox, since they are now part of your browser.About the program, "Firefox Preloader": it DOES speed up Firefox startup since it loads the browser to memory since boot, and as a result it lengthens boot time.  This is as advertised, and in that respect, it works.  It works to the extent that Firefox (now version 3.5.2) starts up faster than a fresh install of IE 8.  However, because the Preloader leaves firefox in memory even after closing the browser, you will get occasional issues like what another poster mentioned, titlebars w/no window, not closing properly, minor issues with updates, etc.  I'd also like to add, by design it doesn't clear my history upon shutting the browser as I intended in my Firefox settings - e.G. Mail remains logged on even if I close the browser.  When using the preloader, I therefore have to Ctrl+Shift+Del to clear everything before closing the browser, to ensure history is gone.  (I checked everything in the clear history settings, and Preloader makes it so I still have to key-combo my history away).Off topic, from an end-user standpoint, compared to Firefox, IE 8 has horrible performance opening new tabs in general.  That by itself is enough for me not to use IE 8, though accelerators and web slices are good ideas I must admit. 

the reason firefox loads so slow is because of addons and updates create a new profile firefox.Exe -p to open profile manager firefox must not be running create a new profile and set it as your defalt you will lose your apps but firefox will start up faster.  you can use three extensions  called CLEO, FEBE and OPIE and save all you addons and settings in a single file and reinstall them.  while your looking at your extensions disable some you don't need like ridiculous amounts of toolbars.  also see of there are any addons that combine some you have like tab kit has colors tab manipulation and other stuff that has individual addons you may be using.

also I think this is relevent 

https://wiki.Mozilla.Org/Firefox/Projects/Startup_Time_Improvements

1. Un-Check ALL FireFox auto-updating... Tools > Options > Advanced > UPDATE
   (uncheck FireFox, Addons, & Search Engines) *Restart FireFox & Time The Next Load*
   
2. Uninstall all junk toolbars, & extentions... Tools > Add-ons > Extentions
   (Remove ALL crap not being used) *Restart FireFox & Time The Next Load*
   
3. Create a FireFox shortcut on your desktop (If one is not already there)
   Right-Click the desktop, choose New > Shortcut
   Enter "X:\Program Files\Mozilla Firefox\firefox.exe" /MOZ_NO_REMOTE -prefetch:1 as the location...
   Type FireFox as the Shortcut Name
   
   or...
   
   Right-Click the exsisting FireFox Shortcut, & choose Properties.
   Select the ShortCut TAB at the top...
   In the Target Location box (Target:) add a space at the end, then add /MOZ_NO_REMOTE -prefetch:1
   It should now look like this: "X:\Program Files\Mozilla Firefox\firefox.exe" /MOZ_NO_REMOTE -prefetch:1
   
   Remember to replace the X in the above "X:\Program Files..." with the appropriate drive letter of your system. ie: "C:\Program Files..."