Error code 25 can generally be linked to your graphics card. If possible swap out the card with a known working card. If the issue persists try the card in another slot if applicable. If the system boots either fully, or to asking you to move the card to the primary slot, you have a defective slot. If the system remains with error 25, try removing any PS/2 devices. This error can also be linked to the mouse being plugged into the keyboard port and vice versa.