I would check the website for the motherboard and see if they have an updated acpi driver for this board. They may not as it might not have been designed for Win 7. As far as the unknow device that is related to the missing acpi driver. If you can find a driver that will work, then you will most likely resolve that issue too.
When I get a chance I will post some links top software that can better identify your motherboard, which is probably based an intel chipset and then you can check the intel website for drivers.
As for the two processors in the device manager, that is normal for a Hyper Thread enabled board which makes the OS think the cpu has two logical processors.