I need to activate a pre-existing copy of Windows if possible so that the OS does not have to be re-installed. Apparently I cannot update using the Windows Update feature because it asks me to activate and I don't have the original information.
Even not activated windows should be able to update, although admitting i haven't ran 8.1 for quite some time now. Try to activate by KMS_VL_ALL.
It does appear to have activated. However, when I upgraded Chrome, it now says "cannot be run by the built-in administrator account." What should I do now to update Windows as far as it can be on this computer that currently has Windows 8.0 on it?