I personally don’t like the new NavPaneSearch.
You can change the behavior of Ctrl-F to bring up the old ‘Find and Replace’ dialog box.
a) In options, click ‘Customize Ribbon’
b) Click the ‘Customize…’ button to the right of label, ‘Keyboard shortcuts:’
c) Select ‘Home Tab’ in the Categories dropdownlist (on left)
d) Select ‘EditFind in the Commands dropdownlist (on right)
e) Click inside the ‘Press new shortcut key’ textbox
f) On keyboard, press Ctrl key then the F key. ‘Ctrl+F’ now appears in the textbox.
g) Click the ‘Assign’ button
h) Click the ‘Close’ button
i) Click the ‘OK’ button
j) Press Ctrl key then the F key and you should now see the old ‘Find and Replace’ dialog box.