Make sure that your Keyboard and Windows Regional settings are all set to
English (UK). Then run the Office Language Tool and make sure that English
(UK) is set as default and maybe uninstall any other language that you don't
want. Now open Word, Options, Popular and make sure it is set to English
(UK) and again uninstall any unwanted languages (though there shouldn't be
any at this stage). If there are, then something is stopping Word from
saving changes to the global template.