To my knowledge, this laptop may need be fully supported with Windows 8. HP usually has to upgrade the firmware/bios of their laptops in order to support full Windows 8 Compatibility. The bios/firmware of the internals will usually effect if your radio buttons work properly and allow them to change color as they used to with Windows 7.
You can use the following link in order to check if your laptop is compatible or not with Windows 8:
http://www8.hp.com/us/en/ad/windows-8/instructions.html
Furthermore, you can check the following HP article if, in-fact, your laptop does support Windows 8: