No version you have mentioned here is compatible with Windows 8. Based on information found on the official manuals, you can install OrCAD 16.6 on the following versions of Windows operating system.
System requirements:
- Windows XP Professional (SP3 or later) 32-bit; Windows 7 Enterprise, Ultimate, or Home Premium (32-bit and 64-bit); Windows Vista Enterprise, Business, Ultimate, or Home Premium (SP2 or later) (32-bit and 64-bit); Windows 2008 Server (32-bit and 64-bit).
