Chrome doesn't need you to download Flash as its built in

To reset Chrome search engine

click on the three little bars top right

Settings

half way down the page under Search, ensure that Google is selected

Bare in mid that Chrome uses settings fron Internet Explorer, even if you don't use it

Fire up Internet Explorer, Tools, Manage Addons, Search providers, ensure that only Google is enabled

In Firefox, on the right of the address bar it should show your default search engine, if it isn't Google (G), then left click on the G and select Google