I just fixed mine. It is possible that someone already added this solution & I missed it.
In MS Word 2010 click on File
Choose Options
Click on Trust Center
Click on Privacy Options
at the bottom of this option is Research Options
Click on this and it will open the Research Options dialog box
Click on Update/Remove
It will show you the Reference Books you already have installed.
However, to fix the problem of not having the dictionary or any other options available you need to select the options again, e.g.
Translation (Installed Dictionaries) lists dictionaries that are already installed (these are highlighted in gray)
Click on it and it will highlight the installed options in blue
On the right hand side you are given the option to update
Click on Update & find the next option and do the same.
I chose Bing & it highlighted many choices of language. It will not allow individual countries so I again highlighted Bing and clicked on Update. Once you click on update the Bing Setup will allow you to make choices about the country(ies) you would like Bing
assistance with. Select your choices and click install. You'll get a pop-up that says services were installed.
I continued to select items such as Thesauri, highlighted it and clicked on update.
Once I went through all the choices of reference books I wanted I clicked on Close
On the Research options I clicked on OK
On the Privacy Options I clicked on OK
On the Trust Center Option I clicked on OK
I then opened a word document and did a right click on a word & it gave me back my options that I previously had.
All is good in Word land for me.