Installation issue System platform on a computer with older system platform previously installed

Hi heroes,

I am trying to install system platform 23 on a computer that had an earlier SP version installed. 

Everything has been uninstalled prior to running the 23 installation.  

I still get the following message:

the installation doesnt succeed after that, so I want to find a way of removing this completely before trying the 23 installation again. Has anyone seen this before?