We often look for some fixed serial numbers as an universal id. Usually we can use WMI class to retrieve  some hardware ID as following:

Win32_BaseBoard
Win32_Processor: ProcessorId
Win32_BIOS: SerialNumber, ReleaseDate
Win32_MotherboardDevice: InstallDate
Win32_DiskDrive

We can refer to MSDN WMI C++ Application Examples for some VC++ samples for the usage.But not all of the above WMI class’ instance would return the requested info, it needs the support of the underlying hardware.