I think that the files have been allocated to Wordpad.
What you need to do is:-
(1) Find a document you want associated with the word processor in Open Office.
(2) Left click once to highlight it.
(3) Press the left shift button (hold it down) and right click on the icon.
(4) Select "Open with..."
(5) Find the word processor in Open Office from the list
(6) Tick the "Always use this program to open these type of files" box
(7) Click apply and OK
That should work.