In what Browser, because that's where you make the adjustment so we need to know that.

This link is a bit old but may be helpful,
http://www.digitaltrends.com/web/how-to-make-google-your-default-search-engine/

I do not have any default browsers. They use up a ribbon across the top of my window and most of the time, I want that space for other things. When Bing sneaked in on a software update, I promptly uninstalled it.

What I do is keep a list of addresses to popular search engines in my bookmark list. I put them all under one folder and named that folder something I could remember such as "Search Engines". I have a wide screen monitor so I keep the bookmark window open all the time. Anytime I want to search, I'll open a new blank window and click on the URL of the search engine I wish to use. Soon, the connection is made and I can conduct searches without closing my prime job. The search engine screen sits on top of my work window. I can toggle back and forth between the two windows. When I'm done with the search, I close that window.

Currently, I have 10 search engines bookmarked. Two of those are my favorites.

Yes, but if you choose a default, you can just type your search criteria into the location bar and it will automatically use the search engine of choice to do the search. No ribbon space needs to be used up.
So it's pretty helpful.

Anyway, we'd need to know which browser berk is using to give specific advice.