Please read the following guide about updating your board to allow the use of an Ivy Bridge CPU:
Also it is critically important that you perform the BIOS update correctly, otherwise it will not be right. Doing it right is really quite simple as long as you do one simple thing:
When the BIOS update program asks you to reboot the PC, DO NOT REMOVE the USB flash drive you will be using to perform the BIOS update until Windows completely boots up to the Desktop!
Part of the BIOS update is also performing an update to the boards IME firmware. That does not happen until the PC reboots, really during the board's POST process. Users that removed the USB flash drive before the PC rebooted report issues with their PC afterwards, since the IME firmware is not updated.
The ASRock guide lists the board's software that must be updated after this special BIOS update, which you should do after you install your G2120 CPU.