PHOTO EDITOR not on list of "OPEN WITH" & executable' location unknown

I want this to be the default program to open bitmaps, but it is not on the OPEN WITH list. I use an Xp version of OFFICE, and never had problems actually finding the executable file for PHOTO EDITOR, until using W7. I searched, but could find nothing but SHORTCUTS for it, & their TARGET field always said "Microsoft Office xP Standard." I tried to use the shortcut in OPEN WITH, but...