Pentium J2900 processor microcode update

This processor model regularly receives microcode updates for Linux (from the Intel website). As I know, Windows also provides microcode updates with Windows updates. My PC manufacturer does not provide BIOS updates (Lenovo). I've reviewed ACER's website and is offering BIOS updates for another PC with the same J2900 processor.
It seems to me that microcode updates are also available for Windows … but I'm wondering if Windows Update will update my microcode. I am using Windows 8.1