I made another try.
After cleaning the system I could force a reinstall by adding to the command line “-h” as string. I needed to reaccept the EULA and installation started through without any further questions. When he told he succeeded, he seemes not do to so. On the desktop or startmenu no quick link is generated. Further if I go down to the path of installation and try to manually start Tobii, he reports a problem as “something went wrong, contact your supplier”. If I try to clean again computer from all traces I am stucked as before, that I cant install (except for the -h command string).