Unable to install version 8 as upgrade

On my second computer, a laptop with also W10 the installation of version 8 is interrupted by a message saying that the file “setup.msi” cannot be found. There indeed is no such file on that system.
On my desktop the installation went smoothly, maybe because somewhere I do have that file, but it is for setting-up an add-on application for the flightsimulator. I see no relation to EM-Client. .
What do I have to do to get it installed?
With kind regards,
Piet de Geus