how to set the test-net & Presearch engine as default
First head to
Presearch
Presearch
click the P_ with the magnifying glass and drag it all the way over to the left - that will be your default provider (i would suggest moving the other P_ over as well just to the right of the P_ with the magnifying glass)
Then you're good to go! Enjoy searching on test-net or the Presearch engine!