hello, you have a user.js file present which will overwrite your manual changes after a restart of the browser, please try this: go to the *firefox menu [[Image:New Fx Menu]] > help [[Image:Help-29]] > troubleshooting information, click on profile folder - "show folder", then a new window will open up. <br>in this window look out for a file named '''user.js''', delete or rename this file in case you haven't intentionally created it in the first place and restart firefox afterwards. in addition you might want to run a full scan of your system with different security tools like the [http://www.malwarebytes.org/products/malwarebytes_free free version of malwarebytes] and [http://www.bleepingcomputer.com/download/adwcleaner/ adwcleaner] to make sure that adware isn't present in other places of your system as well. [[How to fix preferences that won't save]] [[Troubleshoot Firefox issues caused by malware]]

Here is a tutorial about how to remove Bueno Search - completely. http://malwaretips.com/blogs/remove-bueno-search/