Now you can navigate through the installing admin user's temp folder and locate the path where TIA Portal V15 / V15.1 is installing and locate the log file(s). In the explorer path area, type, %temp% and press enter. Instead, Alt-Tab to the start menu and launch an administrative file explorer session (search for explorer.exe, then, (maybe shift or control depending on your setup) right-click -> run as Admin). If you want to read the install log file (which gets automatically deleted once you click OK/Cancel to the 'please restart' pop-up dialog during a failed portal install), do NOT click OK/Cancel.
