The back/forward arrows are now at the right of the Navigation bar, you can use customize to move them back to the left side. The drop-down arrow was removed, you now use right-click or hold left click to see the context menu for back/forward.

Back and forward or other toolbar items are missing | Troubleshooting | Firefox Help

• https://support.mozilla.com/en-US/kb/Back%20and%20forward%20or%20other%20toolbar%20items%20are%20missing

Please mark "Solved" one answer that will best help others with a similar problem -- hope this was it.

You can make Firefox 6.0 look like Firefox 3.6.*, see numbered items 1-10 in the following topic Fix Firefox 4.0 toolbar user interface, problems (Make Firefox 4.0 thru 6.0, look like 3.6). Whether or not you make changes, you should be aware of what has changed and what you have to do to use changed or missing features.

• http://dmcritchie.mvps.org/firefox/firefox-problems.htm#fx4interface

There is a lot more beyond those first 10 steps listed, if you want to make Firefox more functional.

I don't know what do you mean by Navigation bar, I can't see any Back/forward arrow at the right...and when I right click, the the back/forward word are disabled.. maybe my husband deleted it by mistake when trying to get rid of the other add ons, if thats the case (if he deleted it by mistake) how do I put the back/forward arrow bottons back again?

If there is no menu bar first use "Alt" to display the toolbars.

Bring up Customize with View > Toolbars > Customize

then in the lower left corner of the Customize Dialog you want it to read

Show: icons

Back and/or Forward wording or arrows will be grayed out if there is nothing in the tab to go Back to or to go Forward to, respectively.

Picture shows approximately what you would see without the menu bar on the top, or with the menu bar on the bottom. Portion of the picture showing how toolbars look with the menu bar has some customizations described in steps 41-46 in the following besides the initial steps 1-10 in the page mentioned in the footnote of my original reply.

problem is solved, thank you so much