Not to sound flippant, but have you tried accessing the BIOS? If the information you require is not there, the simplest method is to open the case and look inside.
If you have no succes with that, or with the Windows Device Manager, you might still be able to locate a utility called "CPUID". There are many versions out there; and one should be able to tell you what CPU you're running.
There are even utilities that can identify the system board, but the problem when utilities is that they leave too much room for errors. Personally, I don't even trust the OS with what it reports, nor do I trust the utilities created by the mobo manufacturers. Nothing beats a good old fashioned peek inside.
Mick
Complacency is the rigor mortis of the soul.