Παιδια για να κλεισει το θεμα και για να βοηθηθουν κι αλλοι βρεθηκε η λυση και πρεπει να σας πω... Απαντηση της Αsrock Please refer below steps: Step 1. You must have a MS-DOS bootable USB * You can refer below page to build MS-DOS bootable flash drive http://www.sevenforums.com/tutorials/46707-ms-dos-bootable-flash-drive-create.html Step 2. Please download MACTOOL here. http://www.asrock.com/support/download/mactool.asp (L1.61B) Step3. Extract the tool MACTOOL to MS-DOS USB and boot to the stick, key in as follow: C:\>mac c [mac ID] <enter> If it runs successfully, it will go back to driver letter with MAC information without error like below: MAC: XXXXXXXXXXXX SUM: XX C:\> How to Write MAC Address of Your MotherboardPlease open the chassis and you can find a white sticker at the edge of board with 12-digit MAC ID. Then extract the tool to a MS-DOS bootable USB flash drive and boot to the stick, key in as follow: C:\>mac c [mac ID] <enter> If it runs successfully, it will go back to driver letter with MAC information without error like below: MAC: XXXXXXXXXXXX SUM: XX C:\> *For early models, please flash the MAC address with MAC Address Writer V1.17F.