The application you have is not compatible with Windows 8. According to the official information, you need to have version 13 to be able to install it in your Windows 8. Version 13 supports the following versions of Windows:
MS Windows 7 Home Premium SP1 (only for STEP 7 Basic)
MS Windows 7 Professional SP1
MS Windows 7 Enterprise SP1
MS Windows 7 Ultimate SP1
Microsoft Windows 8.1 (STEP 7 Basic only)
Microsoft Windows 8.1 Pro
Microsoft Windows 8.1 Enterprise
Microsoft Server 2012 R2 Standard Edition
MS Windows 2008 Server R2 Standard Edition SP2 (only for STEP 7 Professional)
To acquire more information about this application, I strongly recommend you to visit the official website. A new version of the software can be acquire through your local Siemens representative.
