Update: This is solved with the help of DeathBringer.
Hi everyone
I have an 
HP PRO 3500 G2 MT which came with an Intel G2030, I updated its microcode to latest to support i5-3470 which I’m using right now, 
ME version is 
latest 8.1, and I managed to get an i5-3570K but when I insert it and start the PC, I get CPU unsupported message then PC shuts off, I found out that 
i5-3470 and 
i5-3570K share same microcode, so technically it should work, but maybe HP is blocking it somewhere BIOS level.
So that’s the best I could do, now I’m seeking help from the experts.
HP PRO 3500 G2 MT Motherboard : 
H-CUPERTINO-H61-uATX: 4.00
BIOS : 
AMI 80.03
You can find BIOS backup attached
 HP PRO 3500 G2BACKUP.zip
  HP PRO 3500 G2BACKUP.zip (Size: 3.78 MB / Downloads: 22)
N.B. I do have the CH341A programmer.
Thanks in advance.