I have this problem too. It's like using dial-up. So slow that I reverted back to 3.6 today as it just doesn't work. Pages take forever to load. I fell asleep waiting. I couldn't even write a email inside it because it somehow freezes everything and it takes about a minute for the letter to show up on screen after I'd pushed the button down. It's definitely not a hardware issue as I can write emails happily on other browsers and it's not the add-ons I have added either because the same problems persists when they are disabled.

Try changing the about:config settings.

Here's a summary of most of the config settings:

http://kb.mozillazine.org/Firefox_:_FAQ ... ig_Entries

Here's a useful Youtube tutorial on how to change some of the settings:

http://www.youtube.com/watch?v=wGYggczgyo8

and another website that describes some useful tricks:

http://www.techrepublic.com/blog/10thin ... -hacks/719

Geeky stuff, but my Firefox 4.01 did speed up. Turning on the pipelining feature makes a big difference.

Most of those links are incomplete, and that YouTube video has some of the same FUD that has been circulating the internet for the last 7 or 8 years.

Yes, enabling network.http.pipelining is a good and proper "hack". But this one is the most mis-used pref in Firefox.
http://kb.mozillazine.org/Network.http.pipelining.maxrequests
That video recommends a setting of 20, where the max is 8, regardless of what the user sets. And FasterFox is a good way of causing problems for yourself, like getting banned from some forums or download websites.

Here's another video for "Mazorella" Firefox that recommends 150 for that same setting, "to make Firefox 150 times faster".
http://www.youtube.com/watch?v=eU0b00SVnmI&feature=related

In the begining there was netscape navigator then mozilla, these browsers kicked IE's ass for performance and then mozilla became firefox and for a long time empowered users with its speed and extra features even on a slow 56k connection with a 486 and 8MB of Ram. But alas over time firefox grew, update after update things started changing until one day it hit critical mass and then started heading backwards.

Now in 2011 IE is kicking firefoxes ass in terms of speed and resource management but its the newest player in the browser wars in the form of Google Chrome that blitzes them all because it doesnt max out and hog up all the resources it can, it does what it is supposed to do and loads webpages and fast!.

Why oh why have you made firefox a bloated resource chewing monster when the reason for its very existance was to provide a better browser than IE.. its now a memory hogging CPU killer that even after hijacking the entire PCs resources still crawls along at the slowest pace if more than 4 or 5 tabs are in use even on the fastest of computers with 2 or more Gig of Ram..

Come on! WTF there are still users out there with old PCs so how about getting back to the good old days where the idea was to provide a better faster browser which EVERYONE can use even those with old slow computers instead of becoming the same or WORSE than the browser you set out to improve upon...

I hate having to wait for ages after a page has finished loading to be able to move my mouse again because firefox is using 98% CPU even after everything is loaded up and its been left for several minutes doing nothing, I want my old firefox experience back where I could have 10 0r 20 tabs open and everything flying along with firefox barely even registering on the resouce usage..

A browser should barely register in terms of CPU and Memory usage.. Im not talking about a plugin filled addon infested version but a clean install that just doesnt work as it should...

Its gotten to the point that I hate using firfox and am forced back to IE because firefox is just not a browser anymore, despite my persistance in the hope it gets fixed, despite uninstall and reinstall its become nothing but bloat... and try running itunes at the same time... what a freaken joke that is!

Users shouldnt have to troll forums and try this and try that and most wont, its only tech savvy people that do, the average person will just not use it..

what a damn shame...

Try Google Chrome. That one is really fast.

I've tried all these help suggestions I can understand and nothing seems to help. I'm switching back to IE. The excuse that it's because we have an older computer is bogus--I have a new laptop!

@ gameznet

I completely agree with every word you said about Firefox. I'm fed up of it too! Firefox is frozen!

Try this suggestion:

http://forums.mozillazine.org/viewtopic.php?f=38&t=2323823

I found this topic yesterday, Oct. 13, 2011. I've had the same problems since going to 4.x then with 6.x and above it was horrible. I had set up a VM, using MSVM (Microsoft Virtual Machine) of XP installed FF6.x and upgraded to 7.x it worked fine on my old Dell Latitude D520, 1core 1.6ghz Celeron, XP, SP3, 2gig, and the VM had 512meg assigned. I opened tabs galore surfed all over the place and only XP in the VM notified me it needed more Virtual Memory, my vhd is only 1.3gig for portability.

Time to fix my physical HDD XP, sp3 install of FF7.x I found mozbackup @ http://mozbackup.jasnapaka.com/ backed up my 4 years of FF installs on top of the old installations on the same D520. Then I uninstalled FF7.x, did a search for FireFox in Explorer deleted all folders, for some reason on my uninstall program files\firefox stayed with plugins and .js files. I used two reg cleaning apps, Glary Utilities and RegscrubVistaXP. I always use at least two if not 3 since I've found different engines find different reg issues.

I reinstalled FF7 clean, I installed add-ons I wanted using the new add-ons not my backups. I then used mozbackup and added my bookmarks and form info, passwords and names, back into my new profile and so far FF7 has been greatness. With mozbackup one can backup the entire profile then select which functions to reinstall, pretty sweet app. (I'm not affiliated)

Only tweak I've done to FF7.x is override auto disk cache and set it to 24meg. No real scientific reason other than I was lazy and only felt like deleting the 1 on the 1024meg limit, which winds up being 24.

I haven't even looked at about:config and my fresh install of FF7.x even with use vcard hardware acceleration if possible left to default is so far running great. Dell D520 has the Intel 945 pretend 3d acceleration chip.

I am back to using Internet Explorer 8. It is actually much faster than Firefox now. The irony is, I switched to Firefox because Explorer was too slow. Now the roll has reversed. Too bad Firefox got so bloaty.

My firefox is so slow, I have to use Explorer. What is going on. Pages are slow to open or won't open at all.

Come on Firefox Folks your killin us here we though you were the answer to IE. What happened did you sell out? Are you even hearing us or reading any of this? Don't you care anymore? I don't want to go to GCh or back to IE but if I don't I can't surf anymore. I have a new top of the line laptop with W764p. Can we even get an answer from you as to why? Broken Parted

So sad that after all these years I now find IE a better browsing experience. I will now use Chrome and IE for my development work until FF is fixed.

I give up. I have been running Firefox 13.0, but have had same problem with earlier versions. WAY too slow to start-up, slow response and I am on Roadrunner Turbo. I am back to Internet Explorer for the first time in several years. Speed was the main reason I went to Firefox in the first place. I have tried everything. Changed anti-virus three times, followed all of the steps to increase speed at start-up and changed settings to speed up internet response. It is TERRIBLE. Firefox is going away.