In this post, I will cover the Why Is Yahoo My Default Search Engine problem. A lot of users experience Yahoo set as their default search engine—sometimes without their input or action.
This is puzzling and can be quite a hassle. I will discuss possible explanations activating this switch, how to figure out the culprit, and how to go back to the settings you had before the change.
About Search Engine?
A search engine is a web application that assists users in finding information on the Internet by using certain keywords or phrases. It does this by crawling websites, indexing their content, and returning the most appropriate results based on the searches.

Well known search engines such as Google, Bing and Yahoo have sophisticated algorithms that scan their databases and sort the pages. Autocomplete, personalized filters, special user-tailored results retrieval are also among the offered features. With search engines, computer users can browse a great deal of available data on the Net in a fast and time efficient manner.
Why Is Yahoo My Default Search Engine

Software Bundles
The installation of free software is accompanied by unwarranted sketchy practices, which at times default to changing the search engine to logged as Yahoo.
Extensions or Toolbars for Browsers
Some extensions redirect all queries to Yahoo search engine, so it is necessary to change the default one for more advanced browsing.
Malware or Browser Hijackers
Yahoo can be forcibly set as default by malicious programs looking to generate ad revenue by overwriting existing default settings pay-per-click search service due to ad rot.
Changes Done Manually
Your browser could have been intentionally set to default search Yahoo by an administrator or other user.
Device Default Settings
Some devices or browsers might have been shipped with Yahoo as the default search engine.
Is Yahoo a Virus or Malware?
Yahoo is neither a virus nor malware. It is a well-known search engine. But if it suddenly becomes your default search engine without you setting it that way, it might be due to a browser hijacker which is a type of potentially unwanted program (PUP).
These hijackers use Yahoo as a redirect to monetize traffic through ads or tracking. In such cases, Yahoo is just the end-point, not the source of the problem. Deleting dubious extensions or programs will most likely fix this.
Common Reasons Yahoo Becomes the Default Search Engine
Bundled Software Installations
Free programs sometimes have optional features that change your default Yahoo search engine. If you do not pay close attention to every step, these changes can be made without your knowledge.
Browser Extensions That Are Not Desired
Some extensions or add ons especially from non reputable sources may change your browser settings and send queries automatically to Yahoo
Browser Hijackers Or Malware
These are some forms of malicious software that will set Yahoo as your default search engine so that they can make money off of search advertisements and keep tabs on your internet activities.
Other Users Manually Making Changes To Your Device
Expanding on that,Other people who use the same device might have the intention of changing your browser settings to Yahoo.
Settings That Function Off Defaults
New computers as well as some browsers and operating systems will come with a Wer-Wer base search engine set as default.
When You Might Want to Keep Yahoo
Maintenance of Familiar Interface: Yahoo keeps providing a useful search service to users with an organized interface. This means those who value a lot from ease of use and order in navigation will definitely appreciate this.
Well-Organized News and Information Clusters: Besides search, Yahoo offers trending topics, news, finance updates, sports, entertaining materials, etc which usually comes packaged in an all-in-one homepage.
Data Collection Preferences: Unlike other search engines, Yahoo has been preferred for the more obvious reasons. Such as being seen as less invasive through privacy policies.
Yahoo Mail Services: Yahoo mail users would find keeping Yahoo as one of the default search engines very convenient as it allows for the easy flow of services across Yahoo.
Ability To Modify Webpage Controls: Users who enjoy an individualized browsing experience will appreciate Yahoo’s customization ability which allows modification of your homepage materials.
Conclusion
The reason Yahoo has suddenly become your default search engine is probably due to bundled software, browser extensions, or a hijacker changing your settings. Although Yahoo is not dangerous by itself, the approach taken to change your search engine without permission raises eyebrows.
Troubleshooting the issue—whether it’s an extension or a program—can help you regain control. In maintaining your preferred search engine, routinely watch over your browser settings and carefully install new software while reviewing permissions.