I decided to look again for a method to get english on all the buttons and thumbnails on the ribbon.
Instead of going via the browser to microsoft help I went into the Office 2010 Beta, via Windows 7, start, programs, MS Office 2010, outils, preference de langue and in that dialogue box you get taken to the Beta Downloads, when you select, 'How do I get more display and help languages' (except it is in French at this point) mine is now in English and I cannot remember exactly what it said before. It takes you to the downloads, which are quite large, about 850MB or so. Although my laptop is 64bit, my Office is 32 bit which is compatible and more flexible than the 64 version, So you need to ensure that you get the correct download and the good news is that it is free. The Outlook files that the french version created, like the in box are labelled in french still and cannot be renamed, so the only possible way to change would be to delete the email account and re-instate it, I suspect.
A few weeks back I thought I had already tried the above, but perhaps I was using the normal MS download website.