Microsoft is famous for changing file formats every program version or two,
so that the old version wots not of the new version's files...and you have
to go out and buy the new one! However, the closest thing to a universal
text program is probably good old Windows (3.x) Write. While it can't open
newer files, or create them, it can accept pasted-in text and format that
to approximate the original. Better yet, it does it with very little
"overhead" (superfluous bytes readable only by it)...and keeps the text
content together, followed by a short footer containing formatting data,
so you can look at the file in any file viewer and see what it says! It
can also save files in straight ASCII text.