I had it set to do perpetual updates, but at some point it broke.
It said it would update, but then the update would crap out.
Ah well. I fixed it all and got my new Win 10 Pro working on my VM using the following instructions someone had on the Insider Forums.
(Mine was Build 10162 and the following worked quite well!!!Back in the 90's this approach was fairly standard with dated installs that would expire. In order to update if you messed up on some dated install, you would just roll back your system clock.)
It's pretty simple.
How To Upgrade Windows 10 Build 10074 to Build 10240 If You Get An Error When Attempting To Install (Works 100%, should work for other builds)
Right-click the clock in the taskbar and click Adjust Date/Time.
Turn off internet synchronization.
Change the date to anywhere in the month September (or any time between April 29th and October 1st). The Windows Update error may change if you have gone far back enough, however, this will not matter.
Reactivate Windows by going into Settings, clicking the link that says Activate Windows, and activate using the product key 6P99N-YF42M-TPGBG-9VMJP-YKHCF.
Download the Windows 10 Media Creation tool.
DO NOT upgrade directly with the tool. Instead, create a Windows 10 installation media.
Once the tool completes the creation, start the setup program (from the install media you created). If it asks you to install updates, DO NOT have them installed, because of the same reason as above.
Run the tool. If it tries to install updates and it gets stuck, then things were not done correctly. Close the update window (using Task Manager if neccessary) and follow the directions more closely.
It should now start installing.