do you mean that your doc's get opened in wordpad? or they get saved with a wordpad icon?
right-click on a document >> open with... >> if you see word on the list, select it, and make sure the 'always use...' box is ticked
if you can't see word on the list, youy have to use the 'browse...' button, and navigate to the word program (winword.exe), probably somewhere in your c:\program files\microsoft office folder (or similar, i don't have it installed here right now).