It's a bug that somehow seems to have Word misreading temporary files related to the printer currently in use.  You can usually
'unscramble' the display from File=>Print and switch to the printer properties or to another printer then your normal one, or close
Word and delete all files found on Start=>Search and looking for
 ~$*.*;*.tmp
as the name string then restarting Word.

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Recently I've been trying to type something in word, or copy and pasting
something, and it looks really jumbled up like the letter just keep typing
over each other with the end result being a big jumbled black mark rather
than a word.  I thought this had to do with the margins but I've opened older
documents that haven't been edited in a long time and weren't even created on
my computer and they are also jumbled like this.  How can this be fixed? >>

I find that if you restart your computer, it takes care of the problem.