Creo common files installation not possible

Hello everyone!

I had following issue when trying to install the creo 7 application: The common files could not be installed because apparently the creo 7 Platform Services were not installed, althroug the were. The problem should be clear in the attached screenshot.

Here it says the requirements for the common files which are creo 7 platform services are not met. Above it says the creo 7 platform services have been installed. I would like to restart the whole installation process because I had other issues before which I solved but may have caused this one. But I used a License Key from my school and do not know wheter I'll be able to use ist again.

Thank you all in advance!