I need help to get rid of some extensions: although good they have slowed my Computer down(old). But I just can't fine the manager or uninstall anywhere. Help please.

IMHO, "disableMenu" is a good alternative to "tiny Menu" (it completely hide/show then menu bar). Give it a try!
http://genoetigt.de/site/projects/disablemenu

I also enjoy this little tweak : "Merge Firefox Reload/Stop buttons" :
http://mozillalinks.org/wp/2006/09/merge-firefo...

At some point, I realized that although you can't drag the menus onto the toolbar, you can drag the toolbar items onto the menu bar! This allows you to have only a single bar at the top.

Coupled with getting rid of unneeded menus as mentioned above (MenuEditor is an extension that can do this for those frightened of editing chrome files), throbber, Go arrow, etc., this gives a nice, clean Firefox interface. A well-designed, compact theme (Whitehart is my longstanding favorite) helps, too.

Hey, Mitch! Thanks! That worked perfectly.

How can you ditch the throbber? Right-click on the navigation bar (where you see your back, forward, home buttons) and click on "Customize...". Then you can click on the throbber and drag it down to the customize popup box to get rid of it. Hope that helps!

"2. Toss Out the Firefox Throbber!

Ditch the throbber in the upper right hand corner. Each tab has a built in throbber to let you know when a Web page is loading, this main one is not needed anymore. Get rid of it and give yourself some more space. "

Just how do I ditch the throbber?

After installing the tiny menu extension you can get rid of the navigation bar completely by dragging all the buttons and fields to the menu bar and then hiding the navigation bar. (works best with wide screens)

Thanks Andrew for these userchrome.css edits. Some of them I have in place myself. ;) Edited your Lifehacker link too - since it was sorta breaking the layout here. Hope you don't mind!

Thanks for the ideas Mitch. I also get rid of the 'magnifying glass' button and the 'go' button after the search field and the address bar. The userchrome.css code is below:

/*Remove magnifying glass button from search box*/
.search-go-button-stack { display: none !important; }

#go-button-stack, .search-go-button-stack {
display: none !important; }

As well as a the edit and help menus. The userchrome.css code is below:

/* Remove the Edit and Help menus
Id's for all toplevel menus:
file-menu, edit-menu, view-menu, go-menu, bookmarks-menu, tools-menu, helpMenu */
#helpMenu, #edit-menu { display: none !important; }

Mitch, you should have included a link on how to remove the throbber. I had to search to find the userchrome.css adjustments included below:

/* Eliminate the throbber and its annoying movement: */
#throbber-box { display: none !important; }

In case no one knows what I'm talking about these adjustments are added to your userchrome.css file. This is easily accessed through Firefox by going to:

Tools -> edit my config -> chrome editor -> top tab should have userchrome.css already highlighted.

Just copy the desired code to the bottom of this file.

NOTE - These aren't my adjustments they are from here.

Whoops, just realized I was missing the link on the first step. ;) Thanks funTomas for giving it to me!

4. Install Tiny Menu extension (http://firefox-extensions.arantius.com/tiny-menu)