Bat sa windows 7 nakikita niya 4 core and other software? Sa windows 7 naka automatic na yung sa ultra motion ng splash pro pag install so meaning 4 cores siya pero sa windows 8 hindi kasi nakikita ng 8 is 2 cores. I don't believe na 2 core lang ang AMD A10. Sa CPU z and Asus 4 cores.
I don't care how you count cores, I'm just telling you how it works and the reason why Windows 8 sees it as 2 cores. It's a part of the optimization that Microsoft implemented to efficiently use the 2 modules that you have in your APU (whether you count them as 2 or 4 cores). It is possible that they'd patch this cosmetically in the future, but it does not change how the OS allocates threads.
At the moment, Windows 8 reports core count based on how it operates (and it operates with each Bulldozer/Piledriver module as 1 core capable of handling 2 simultaneous threads as a performance optimization). CPU-Z (and your ASUS utility) display 4 cores as this aligns with how the product is sold -- these applications do not do the work of the operating system.
It just happens that Windows 8's core reporting interferes with Splash Pro's feature operation in this case. It is a manifestation of the optimization that they did, as Splash Pro is dependent on what it perceives as core count. A patch on either software (Windows 8 or Splash Pro) could re-enable Motion2 Ultra on dual-module bulldozer/piledriver designs if they're interested in doing so.
If you feel that this is a bug, you can try refreshing Windows 8's core detection by clicking and unclicking the "Number of Processors" checkbox under MSConfig's BOOT Advanced Options, and see if that works. Of course as you mentioned, you can still go back to Windows 7.