I finally got it running on my Win7 Pro machine after 3 tries. I remembered having some graphics driver conflicts with my add-in card and onboard chip, so I pulled the card and then it upgraded fine.
Now I'm just trying to get the cards/drivers to play nice with each other again.
Assuming I'm successful, this will be the first time all of my Win devices will be running the same OS, so I've got that going for me.