Some of my documents appear to have been corrupted as all the text is now
just a lot of "little boxes"...

How can i fix it?

First try highlighting some of the text and see what the font is set to
(FORMAT, FONT) You may simply be able to change it to Times New Roman.

The true novice user method of recovering text from documents should be
1. Go to the end of the document and hit enter two more times This
should add two additional blank paragraphs at the end of your document.

2. Highlight all the text EXCEPT those last blank paragraphs (HINT -
put the cursor at the beginning, hit the F8 button, then use the down
arrow key on your keyboard to extend the highlighting. If you
accidentally include the blank paragraphs, use the up arrow key at
least once so that you are sure not to include them)

3. Click the COPY button on the toolbar. (or you can use CTRL-C)

4. Click the NEW DOCUMENT button on the toolbar (CTRL-N)

5. Click the PASTE button on the toolbar (CTRL-V)

6. If needed highlight all the text in the new document and use this
key combo: CTRL-SHIFT-N to force all the text to be formatted as plain
text. Save the new document, and recreate the formatting that you need
the new document to have. Save again.