Here's the process to roll back:

First, I recommend backing up your Firefox settings in case something goes wrong. See Backing up your information. (You can copy your entire Firefox profile folder somewhere outside of the Mozilla folder.)

Next, download and save Firefox 3.6 to your desktop for future installation. http://www.mozilla.com/firefox/all-older

Close Firefox 4.

You could install Firefox 3.6 over it (many have reported success) or you could uninstall Firefox first. If you uninstall, do not remove your personal data and settings, just the program.

Unless you have installed an incompatible add-on, Firefox 3.6 should pick up where you left off. If there are serious issues, please post back with details.

Note: I haven't actually tried this myself!

You can make Firefox 4.0.1 look like Firefox 3.6.17, see numbered items 1-10 in the following topic Fix Firefox 4.0 toolbar user interface, problems (Make Firefox 4.0 look like 3.6)

If still not convinced the next section on that page is Running both Fx3 and Fx4 or Returning to Fx3 (#backto3pt6)

Ok, Thanks. The one thing you evidently missed in my question/post was that I already un-installed FireFox, because it was continually locking up, and it was sooooo much S L O W E R, than the previous version.

Will try your link to get 3.6 back in again.

I just wish that when an outfit like FireFox SCREWS UP as badly as they did when they released version 4, is that they would have the GUTS top admit it, and advise us of cures!

Thanks for your response!

I want NOTHING to do with FireFox 4 the way it was screwing around with my new HP 'puter!

N O T H I N G that even looks like it!

Actually that link to FireFox 3 refused to download.... get the message that the file is corrupted!

Getting rid of your Ask toolbar would be a big help. My Fx4.01 is working beautifully and, with some customization, looking good.

You may not want to give Firefox4 another try - I'm not fussed either way. I'm just another user like you, as are virtually all the contributors on this forum . Many extensions, plug-ins(such as Flash), anti-virus programs, toolbars etc are updated as well as Firefox and new problems and conflicts can develop.

If you do decide to give Fx another go, you could read this -

http://www.mozilla.com/en-US/firefox/features/

and work through this(Safe Mode, Problematic extensions etc) -

https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes

It doesn't take that long. Make sure you have the default theme. You could also try disabling Hardware Acceleration -

Options>Advanced>General>Browsing>uncheck "Use Hardware Acceleration . . " If it works better you may need to update your graphics card.

You may not be back but others might find this helpful. A piece of advice, don't put your email address on display in a public forum.