I cannot install Windows 8 on a Toshiba Satellite

Hi there! A friend of mine recently bought a Toshiba Satellite C850-B559 laptop. It came with Windows 8, but ´cause he does not know much about computers, he gave it to a third person who formatted the whole hard drive and installed Win7. The problem is, that a couple of features of the laptop, only work in Windows 8. And he would like to reinstall Win8, the problem is that when the formatted the HDD, they lost the backup partition, and due to that, in the installing process, Windows does not find the HDD. It says that it can´t find the HDD driver. MAybe the problem is that is in configured in RAID mode on the BIOS (which i´m not sure, ´cause i haven´t seen the computer, he lives far away), but it should be recognized anywhere. We contacted Toshiba Support in the US trying to find a way to recover the backup. But since the laptop was bought in Portugal, they say that it is a problem of Toshiba Europe. What can we do? Is there a way to reinsatll it without the support center? THanks!!!