Download CPUz executable file and run that. It will give you the motherboard information under the motherboard tab. Unzip it and run CPUz.
https://www.cpuid.com/downloads/cpu-z/cpu-z_1.91-cn.zip
Give us some backstory on this system.
Where did you get it?
Logo on the case?
Print on the actual motherboard?
Nothing actually printed on the motherboard?
(why would you buy a system and not know what was in it?)