This post onMiniTooldiscusses how to make Cortana use Chrome, not Edge.
Most users still prefer to use browsers like Chrome than Edge.
you could also set Firefox or another online window as the default one by this way.
How to make Cortana use Google?
you oughta download a free tool like EdgeDeflector first; then, install and run it to select Google.
Full Fix: Google Chrome Not Working (Not Responding/Wont Open).
Thus, you still need to set Chrome to fire up the Cortana search results in Google.
Thats the steps to make Cortana use Chrome and change Cortana search engine.
