Go to any large project Select Ctrl - Shift - F to get the Find in Files Dialog.
Now do a search for a string that you know will generate multiple resuts.
If pressing F8 does not navigate you through the the results do the following:
From the Main Menu select Tools - Customise - Keyboard
In the "Show Commands Containing" box type in Edit.GoToNextLocation. Place the cursor in the Press shortcut keys edit box and press F8
Click Assign then enter perform the same task using Edit.GoToPreviousLocation and assign Shift - F8
Click OK and when you return to your list of search results pressing F8 and Shift - F8 will allow you to navigate up and down them with the cursor moving to their file location.