To revert to Bing as your preferred search engine, please do the following.

• In the location bar, type about:config and hit Enter.
  
  
• In the filter at the top, type: keyword.URL
  
  
• Double click it and remove whatever's in there and replace it with http://www.bing.com/search?q=
  
  

The URL to add in "keyword.URL" becomes a link in this post, so right click it and choose "Copy Link Location" to copy it to the Windows clipboard. Then hit CTRL+V to paste it. Saves you having to type the whole thing.

To reset your home page, do the following.

• Go to the site you want to set as your homepage.
  
  
• Click the orange Firefox button and go to Options | Options | General
  
  
• Make sure it says "Show My Homepage" in the first dropdown menu.
  
  
• Click the button called "Use Current Pages" to set the homepage to the one you have on the screen.
  
  

After you complete the above steps, install this add-on to prevent another search engine from modifying your preferences: https://addons.mozilla.org/en-US/firefox/addon/browserprotect/

Hi thanks for pointing me in the right direction about deleting Speedbit BUT what you have said is not the full story - after you have done the keyword URL and deleted speedbit there, type speedbit in the filter and press enter and then change all occurences of speedbit to the browser you want to use - after 1 week of trying various ways to remove speedbit this appears to work. PS I have also previously deleted all occrences of DAP and SPEEDBIT from my registry. FINALLY I THINK ITS TIME SOMEONE SORTED THIS COMPANY OUT - I KNOW I DECLINED ALL EXTRAS WHEN I INSTALLED DAP so clearly they have no regard for the user only for themselves.

I have posted the solution here. Goto the last of the page and you shall find the solution.

https://support.mozilla.com/en-US/questions/797953#answer-169330

Nothing seems to work.

I have (a) Done precisely what upk_singhm said above

           (b) Used Regedit to get rid of all references to speedbit
           (c) Uninstalled anything and everything to do with Speedbit     

I even used speedbit's own utility - THAT WAS a disaster - should have known better - it actually renamed the Google search in the search bar to speedbit.com ... very nasty indeed.

STILL COMES BACK!

This is evil stuff ..... will never, ever have anything to do with DAP or speedbit again. Strongly suggest everyone ditches it pronto.