Hi Sebastian,
Based on your screen shot, it looks like the OneClick Web server, and Report Manager, have already been installed on this server.
You can verify this by looking for the $SPECROOT/tomcat directory on the server. If that directory exists, then OneClick has already been installed. If this is a Windows system, check the Services to see if there is a "Spectrum Tomcat" service installed and running. If this is a Linux/Solaris server, you can run the "ps -ef |grep -i tomcat" and see if there is a java process running that is associated to tomcat.
If Tomcat is running, then you should be able to access the OneClick Web server that is installed on this system.
Thank you,
Brad