Microsoft makes it close to impossible if you are talking about the search that you find on windows key pop up. You can change the default browser will change what is launched if you would click on a web search result.
The problem is that search box search the local pc , stuff you have stored in microsoft linked to your account, and then the internet. You will find registry hacks that people have disabled the ability to search internet but microsoft constantly changes stuff so these do not always work. The latest is their stupid AI stuff that like contera you can only hide a but not actually fully delete.
I really wish linux was a valid alternative to microsoft bloatware.
Not sure if someone has figured out how to registy hack the latest search since they added the AI patch. I know they key way to block most microsoft stuff is to use a firewall and block all the IP addresses microsoft uses. This though has gotten more complex since even microsoft is starting to use their competitors data centers like cloudflare, amazon, akamei,etc