I keep seeing variations of this post, saying "Just upgrade from the full .ISO. It's easy." Well, that may be true for some or even most, but it isn't true for me and for others I've read on this forum and I find it disingenuous to suggest that that approach solves all of the problems people are having.
For me, using the ISO, I run into the problem where it's asking me for a valid product key. When I enter my valid Windows 7 key, it says it's not valid and doesn't allow me to skip it.
If I use the 'upgrade in place' method using the media creation tool by Microsoft, I run into the problem of not being able to accept the licensing terms because my uninstallation of VMWare Tools, including the SVGA driver make the 'Accept' button on the acceptance page go off-screen and no amount of <Enter> key combinations or tab keys seem to get me past it.
Really, this experience has, by far, been the worst (and most time-consuming) upgrade experience I've had and VMWare Fusion has been a key contributor to the problems encountered.
NOT A HAPPY CAMPER.