Hi,
Could you please check these notes.
2066345 - NWBC for Desktop 5.0: Prerequisites and restrictions
NWBC for Desktop Installation - SAP NetWeaver Business Client - SAP Library
It will help to provide correct environment for NWBC.
SAP GUI for Windows 7.40
Microsoft .Net 4.5 and Microsoft Visual C++ Redistributable for Visual Studio 2012
Microsoft Visual C++ Redistributable for Visual Studio 2012 is included in SAP NWBC 5.0.
If you do not have Microsoft Visual C++ Redistributable for Visual Studio 2012, it is automatically installed with SAP NWBC 5.0.
As well as the necessary PAM.
Especially Windows 8 is less supported compared with Windows 7 and Windows 8.1. Amazingly Windows Vista with IE 8 is supported longer than Windows 8.