You can't change default font style by simply opening an existing document and changing its font style.
The default font style is something you set within Word so that the next time you want to create a new document in Word the font will automatically be set to the previously specified font style and font size.
What kind of characters are you not able to see?...
To set default font style and size in Word 2010
- Close all open documents and close Word.
- Start Word!
- Click File on the upper left corner.
- Click New, click Blank Document and click the Create button on the right.
- Click Home button on the toolbar.
- From the Font group click the Font flyout (small arrow button).
- From the Font list, select Arial Unicode MS.
- From the Size list, select the font size you want.
- Click the Set As Default button on the bottom left.
- When prompted select All documents based on the Normal.dotm
- Close the document and close Word.
The next time you start Word the font style and font size will be automatically set to the style and size of your choice.
To enable Unicode characters
In order for you to see the Unicode characters such as Ć, Č, Š, Đ and Ž, or Chyrilic characters such as А, Б, Ц, Д, Е, Ф, Г, Х you need to tell the writer of the original document to use a font style that supports it, such as Arial Unicode MS.
The font style is saved with the original Word document, not in Word
If the writer of the original Word document has not chosen to type
the document with a font style that supports these characters, then
there is no way for you to add this support on your end by choosing
default font style in Word.