Q: why did my default search engine change from google to yahoo? and how do i get google back?

A plug-in or add on could have asked or forced this without your consent.

Close Safari

open Safari holding down the SHIFT key

go to Safari>Preferences

go to the General tab

change your homepage

go to the Search TAB

change your search engine

for other browsers refers to their support documenation

https://support.mozilla.org/en-US/kb/reset-preferences-fix-problems

https://support.mozilla.org/en-US/kb/reset-preferences-fix-problems

go to safari settings / search. There you should enable google again.

greetings from germany

Chris

Please disable all Safari extensions and test. If the problem is resolved, re-enable the extensions one or a few at a time until you find the culprit.

Did you try Linc's suggestion?

how to i undo extensions?

By clicking the link in my earlier comment and following the instructions.

Newybaby wrote:

 

i cannot figure out how to do all that. how to i undo extensions?

Quite easy.  Go to Safari Preferences --> Extensions

Click on each extension you have installed and then press "Uninstall."