If the driver is not showing up when you use the service tag to look for it, download the driver manually. For the video, you must install the Intel driver first - then reboot and install the AMD driver.  Before starting that, be sure you see two entries under Display Adapters for the two GPUs. If you don't, either the replacement board has no AMD GPU or it is faulty.  
help dell,   i have an inspiron 5559 that originally had a core i3 in it.  the mobo died so i purchased a mobo for the 5559 with a core i7 on it and discreet amd graphics.  the board asked me for the service tag number so i entered the one on the machine   what a mistake. when i went to udate the drivers it ha a bios update and i mistakenly clicked on it and it installed the bios for the original mobo with the core i3.  i am desperately trying to get the proper bios for the core 17 with the amd graphics. how can i go about getting it so i can roll it back to the proper bios?
man i messed up