Hi,
I have Inspiron 3542 with Windows 8 that I want to upgrade to Windows 10 using DVD. But, at the time of installation it asks for the CD Key. I have downloaded product key finder from here:
which is showing me the product key. But when I enter it, the updater shows:
"This product key didn't work. Please check it and try again, or try a different key."
Why? I have genuine activated Windows 8, then why the key is invalid? And what should I do now?