You have to contact Sony support and order installation media, you can't just use any OEM disk. Support for OEM installations is usually handled by manufacturers themselves and, at least in my country, Microsoft support always redirects me to them.
Installing from another media might work, but may cause you update/licensing issues.
Of course if you have an installation DVD that came with your computer, go ahead and use it.
Since Ramhound suggested that Windows 8.1 will accept any installation media with any key I've contacted Microsoft and, as I expected, they informed me that installing from different media will most likely not work. I am also planning to replace my HDD with an SSD, so I tried using OEM Windows 8.1 install DVD I bought earlier for a laptop on my computer that came with Windows 8.1 OEM, and it failed to install.
Bottom line is you got lucky, or you have install DVD from the same manufacturer, but generally this will not work most of the time.