why does my search engine keep going to bing it changes to installmac then to bing

Probably is the result of an adware or popup situation that best be cured before

the issue would go away. Re-setting the search engine default, only, will not fix it.

The malwarebytes for mac (from maker site) is good to cure several ailments; also

etrecheck (from maker site) has a good array plus report to show ASC. Some ideas

that may help, are told about in this site/page:

• How to fix when Safari gets redirected to Bing on your MacBook - AppleToolBox

Also some users who installed dubious 'mac cleaner' products can get the redirect

as a side-effect of introducing adware/malware/junk software into their Mac.