Toto tu by ti malo vygenerovat instalacku, ak tam zadas platny product key
http://windows.microsoft.com/en-US/windows-8/upgra de-product-key-only
product key mas niekde na stitku a v ACPI, to si mozes vycitat napr. pomocou RWEverything z tabulky MSDM http://www.nextofwindows.com/how-to-retrieve-windo ws-8-oem-product-key-from-bios/