AJAX and Content History menu items are displaying in the components menu
From Joomla! Documentation
Revision as of 00:56, 14 November 2013 by NickSavov
What is the cause
When a site is upgraded from Joomla 3.1 to 3.2 using FTP or another manual upgrade, a number of extensions show up through the discover install method. When Discovery Install is used for those extensions, AJAX and Content History show up in Components sub-menu.
How to fix
Create a backup, then delete the "com_ajax" entry in the _menu table (you can search for it in the title column). Afterward, delete the "com_contenthistory" entry in the same table.