Internet Explorer and Firefox have built-in search tool but if they use a search engine you dislike, they're of little use. To change the search used by Internet Explorer, click on the small arrow next to the magnifying glass icon in the search box and select Find More Providers. Click on the link for the search engine you want, then tick the box labelled 'Make this my default search provider' before clicking on Add Provider.

To do the same in Firefox, click on the small arrow to the left of the search box and select Manage Search Engines. Use the Move Up button to the right of the dialogue box to move your preferred search engine to the top of the list and set it as default.