|Right-click one of the files, click "Open With" then click "Choose Program". If the Office application isn't listed in that box, click "Browse...", then go to the following folder:|
C:\Program Files\Microsoft Office.
If you have Office 2003 go into this folder:
If you have Office 2007 go into this folder:
If you have Office 2010 go into this folder:
In that folder you should be able to find the .EXE for the Office Program. For example, Word is WINWORD.EXE in that folder. Excel is EXCEL.EXE and PowerPoint is POWERPNT.EXE. After selecting the program, it'll appear in the list.