I tried what Paul Thurrott talked about, going to
Upgrade Windows with only a product key - Microsoft Windows Help and selecting "Install Windows 8.1" but when I had to enter my key it was not valid. The key was an online purchase for Windows Pro 8 upgrade back when it was only $40.
This sucks, because now if I want to rebuild my system, I have to install Windows Pro 8, then do the 8.1 update. (Yep, I already went through the process. After I already did the update. Just experimenting).
Now, I also tried to create a recovery disk after the update to a USB drive. It's only 282 MB of files. WTF?!?!?!?!?!?