Also, in some browsers the Google homepage is stored and even if you are offline the page opens up. Please check if you can reload the homepage or sign in to your Google account.
Try restoring your browser to default state and check for any software in Control Panel that may not look familiar and uninstall that.
Steps to fix if Google search not working-
Step 1: Open Settings on your Android phone and go to Apps/Applications Manager.
Step 2: Go to Settings > Apps /Application Manager > Google.
Step 3: Then tap on Storage followed by Clear Cache. If this doesn't work, you should try the option called Clear data/Storage.