Don't you mean the about:config page?

You can consider to use code in userContent.css to disable some about pages.

Add code to the userContent.css file.

• http://kb.mozillazine.org/userContent.css

@-moz-document url(about:config){window{display:none !important}}
@-moz-document url(about:support){html,body{display:none !important}}

The customization files userChrome.css (user interface) and userContent.css (websites) are located in the chrome folder in the Firefox profile folder.

• http://kb.mozillazine.org/Editing_configuration

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

iam try it, and i cannot found userContent.css or chrome folder on %appdata% windows xp environment

iam try it, and i cannot found userContent.css or chrome folder on %appdata% windows xp environment

This file isn't created automatically.. You have to create it yourself.
You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

See also:

• http://kb.mozillazine.org/Profile_folder_-_Firefox

You should open a text editor (like Notepad) and when you are done, save it as userContent.css with the file type as ALL FILES or else you will get a file called userContent.css.txt which won't work.

thanks br