hello Katrina88, please install the search reset addon - it will revert the most common customizations those adware programs do in firefox back to the default: https://addons.mozilla.org/firefox/addon/searchreset/ also go to the windows control panel / programs and remove all toolbars or potentially unwanted software from there and run a full scan of your system with the security software that you have in place and different other tools like the [http://www.malwarebytes.org/products/malwarebytes_free free version of malwarebytes] & [http://www.bleepingcomputer.com/download/adwcleaner/ adwcleaner]. [[Remove a toolbar that has taken over your Firefox search or home page]]

How sweet packs coming back? As popups or homepage or other forms? See here [http://howtovirusremoval.com/get-rid-of-start-sweetpacks-com-virus-fix-redirect/ Remove Sweetpacks]

Katrina, try [http://deletemalware.blogspot.com/2013/04/how-to-remove-start-sweetpacks-and.html this removal guide]. Then scan your computer with Malwarebytes and AdwCleaner.

Thanks for your advice. I've managed to get rid of the problem, 'fingers crossed' it won't come back.