Firefox is highly customizable and you may be able to customize it to meet your needs.

If you do not like the new UI, you can make Firefox 4 look and behave more like Firefox 3.6, for details see http://www.computertechtips.net/64/make-firefox-4-look-like-ff-3-6

To downgrade to Firefox 3.6 first uninstall Firefox 4, but do not select the option to "Remove my Firefox personal data". If you select that option it will delete your bookmarks, passwords and other user data.

You can then install the latest version of Firefox 3.6 available from http://www.mozilla.com/en-US/firefox/all-older.html - it will automatically use your current bookmarks, passwords etc.

To avoid possible problems with downgrading, I recommend going to your profile folder and deleting the following files if they exist - extensions.cache, extensions.rdf, extensions.ini, extensions.sqlite and localstore.rdf. Deleting these files will force Firefox to rebuild the list of installed extensions, checking their compatibility, and reset toolbar customizations.

For details of how to find your profile folder see https://support.mozilla.com/kb/Profiles

Why did they change the button layout? My guess is to look and feel more like chrome. I have xp. I realize you can change the button layout, only problem is when I clean my browser with reg mechanic, it resets to the AWFUL new layout that puts the home button on the far right, after that useless tool bar (WHO USES TOOL BARS?!?!? Annoying!!) Up to 3.6 the arrangement was constant. Why mess with a good thing? In addition to this annoyance, 4 crashes much more often that 3.6 did. Please fix this or I will just go to using chrome exclusively.

i hate firefox 4.0 too.

http://www.computertechtips.net/64/make-firefox-4-look-like-ff-3-6 - doesn't give desirable result. All the same much doesn't work normally.

I too do not like the new layout. So far, I am not pleased with 4.0

It looks terrible..I just upgraded..now getting ready to uninstall and go back to 3.6. What is up with the tabs ways the heck on the top?..they should always open under the browser bar. It is so distracting . I love Firefox..but not this..

oops..just found out how to get the tabs back where I wanted them..all is good.