That are menu entries that you see in the orange Firefox menu button pop-up and not in the History menu that you see on the menu bar.

The orange Firefox menu button is hidden by default on Windows XP.
You see the orange (on Linux gray) Firefox button if the Menu Bar is hidden, so you need to hide the Menu bar to get the new appearance.
If you need to access the hidden Menu bar then press F10 or hold down the Alt key to make the Menu Bar appear temporarily.
You can place the Tab Bar on top.

• View > Toolbars : [ ] Menu Bar
• View > Toolbars : [X] Tabs on Top

I checked out the the entries under Firefox menu. There is one entry for "History" option. But, there are still missing features when compared to Firefox 3.6. The only available features in "History" seem to be "Show all history" and "Clear Recent History". The only feature in "History" of the Menu bar is "Show all History". Clearly, something is missing at both locations. Any further leads ? Thanks for your suggestions cor-el.

Some menu entries are hidden by default and only appear if you use the keyboard to open the menu.

You can see the difference if you use Alt+F and Alt+H and Alt+B to open the File, History, and Bookmarks menu and compare that to what you see if you use the mouse to open the menu after you have made the menu bar visible by tapping Alt or by pressing F10.

I tried Alt+H and it activates the Help menu instead of History. I don't know which key to press for History menu. According to Firefox Help, the entries missing in History menu are Back, Forward and Home.

I tried Alt+s and it activates all the entries listed in Firefox Help. This solves this problem for now. The other thing is I can't activate Firefox -safe-mode by "Start->Run->firefox -safe-mode" in Window XP. The safe mode version of Firefox 4 doesn't show up in the applications programs. Any suggestions ?

In Firefox 4 you can use one of these to start in Safe mode:

• Help > Restart with Add-ons Disabled
• Hold down the Shift key while double clicking the Firefox desktop shortcut (Windows)

I tried all possible options to activate safe mode of Firefox. The only one seems to be working is with "Help>Restart with Add-ons Disabled". I don't know why ? Thanks again cor-el.

Hey co-rel, now I'm stuck in safe mode. I first closed the window accidentally and then I tried to re-exit File. But, all this doesn't work. Do you know how to get out safe mode ? All the Add-ons are disabled. Do you know how to re-enable these add-ons ?

Do you mean that you get the Safe mode start window every time that you start Firefox?

I think I fixed the problem. It seems I was out of the Safe Mode start window when I started Firefox. I also enabled all Add-ons. Thanks again for the help, co-rel.

You're welcome