I have a silver Macbook Pro. Not sure of the exact model, it has a 250GB HDD and a DVD drive. I am having issues reinstalling Mac OS. I have reset many Mac computers and never seen this issue. I tried via USB. I plug in the USB (I have 2, 1 with El Capitan and 1 with Mavericks) When I hold down Option during boot, it won't go to the drive select. I goes straight to MacOS Recovery. I tried holding down Option, Command, + R to go into internet recovery. It won't load that either. I tried resetting the PRAM, by holding P, R, Command, and Option till it's supposed to do the Mac start up chime. It never does, just goes to MacOS Recovery. Inside Mac OS recovery I try to format the top drive. It gives me an error, couldn't unmount the drive. I tried repairing, it found no issues. I tried a few different terminal commands from various guides I looked up, nothing is working.