To make Google as your default search engine do as following:
First go to Tools menu on your Internet Explorer, click on Manage Add-ons..., on the left pane click on Search Providers, than on the right pane you will see the name bing, go in the left down corner and click on Find more search providers... find the Google Search Suggestions and click in Add to Internet Explorer, after that close the Manage Add-ons window and Open it again, go to Search Providers, right click on Google and chose Set as default, than right click on bing and click Remove. At the end click on Close and restart your browser.
This is it.
Cheers.