Error Installing Microsoft Office Trial

[JellevM]

Hi i get a error if i install Microsoft Office Professional (Trial version)
this is the error (its in dutch):

Er wordt al een installatie uitgevoerd. Klik op Opnieuw zodra die
installatie is voltooid of klik op annuleren als u de installatie wil
beeindigen.

Now the translate to english if you arent dutch:

There is already a plant. Click once again that installation has been
completed or click Cancel if you want to end the install.

please can someone help. i think i go buy the full version but first i will
try it