I am upgrading a 6-month old SONY VIAO Z-series (Core i7 processor ) running Windows-64 bit to Windows 8.
I bought online this morning the Windows 8 upgrade program -which checks if the laptop can be upgraded; and was provided a Product key by Microsoft.
When running Windows 8 installer, the product key (provided by Microsoft after the puchase is approved) is considered "invalid" in the installer program and you therefore can't click on the "next" button. So nothing is happening and you have to quit the program.