What's wrong with my Google Chrome browser?

[AZJonnie]

6. Actually, you were likely already in the Chrome browser when you did that

What you did was set your default search engine in Chrome back to Google, which had been changed to another one.

The default browser (a Windows level setting) was likely not the issue, the default search engine within Chrome was.

Because the default search engine changes which site/page comes up with you first fire up Chrome from the Chrome button (which you said you did), you went to an unfamiliar looking page and concluded you weren't in Chrome, but you actually were. You just weren't at google.com. And the icon you saw on that page you arrived at was probably "Google", not "Chrome".

Reason it got changed is likely you clicked Ok on something at some point without reading all of what it said it would do, but it's worth running a full malware scan just in case