I bought a Windows 8.1 OEM version (at that time id dint know what was for) to install it on my fresh new self built computer but because the hard disk reviled to be defected the installation was not successful although the process seemed to be completed. So i bought a new hard disk, returned the Windows 8.1 to the shop and bought by amazon a 8.1 full version (vanilla box) because the oem installation seemed too much difficult for me... Now the question: i ear somewhere that the 8.1 OEM installation leaved a key (?) on the bios, what will happen when i install the retail version, will i be able to use its proper product key?