Installing Microsoft Office to Venue 8

Just bought a Venue 8 Pro.  Great device but have a problem with installing the preloaded Home & Student Microsoft Office software.  I have a product key (supplied with the machine) and entered the key - which got a little green arrow indicating that it was accepted and the screen then showed that activation had been achieved and then that there was a problem with Microsoft Office.  A new small window then opened showing that Windows was searching for a solution which, presumably, it found as I then got the promotional video extolling the virtues of Microsoft Office.  However, after the video completed, all I got was a blank screen.  After waiting for a few minutes, nothing further happened so I closed the screen then attempted to start Microsoft Office via the icon but it just took me back to the activation screen.  have tried this several times with the same result - what am I doing wrong?