When your only reason to mod your bios is because you want to upgrade the microcode, you might want to rethink that. Why wait for a bios update or perhaps a microcode update via windows update?

https://labs.vmware.com/flings/vmware-cp...e-update-driver
This VMWare fling is installed as a driver, and in the event log you can see if a microcode update has been applied.

You just grab the latest microcode files from intel and AMD, and off you go.
Use these microcode files:
https://downloadcenter.intel.com/downloa...ocode-Data-File
https://github.com/OpenELEC/cpu-firmware...mware/amd-ucode
The driver wants/needs both intel and amd files, for some reason.

Anyway, this works great, especially if you have a number of PCs to maintain.