mac os x el capitan wont startup (not even in safe mode)

. I tried fixing a freinds computer and I first went into this utility mode and tried to reinstall El Capitan but it wouldn’t install because the recovery hd could not be installed on or it was locked. The other option (installing on the OS X Base System) would make me sign into the Apple Store and after I did it would say “this item is temporarily unavailable” I also tried to boot through a startup disk (I have a startup dvd). I also tried to erase and first aid every drive but that didn’t work either. I also don’t have a Time Machine backup. please help. Images that help