Spellcheck dictionary in Thunderbird

I have downloaded and installed the UK English spellcheck dictionary in Thunderbird but when I go to use it, the only one there is the US English. How do activate the UK English as the default? When I was using Mozilla 1.x, it appeared without any problem

 

boutells,

Apologies for having taken so long to answer your inquiry!

This is the Thunderbird KB article on how to install a Dictionary:
http://kb.mozillazine.org/Dictionaries_(Thunderbird)

Open a new message by clicking on: Write. You should now be able to select the Dictionary here: Options | Check Spelling
Keep in mind you must be in the "Message" pane
Then click on the down arrow in the "Language" field and select the appropriate dictionary.

When you select the English (United Kingdom) Dictionary from this page:
http://www.mozilla.com/thunderbird/dictionaries.html

ensure that you right click the file (spell-en-GB.xpi) and save it to your HDD.
Next:
Open TB, click on Tools | Extensions
Once the Extensions window is open, then right click and drag the spell-en-GB.xpi file from the HDD, to the Extensions window. It should then install, but won't be viewable in the Extensions window, once installed.

Now open a new message window, and check the Language field. Both the English (US), and the English (United Kingdom) Dictionaries should be listed.