This was a Windows problem. Here is what worked for me.
Open Control Panel.
Click on Uninstall or change a program.
In the left column of the window that opens, click on Turn Windows Features on or off.
(You can also search for "turn on windows features" and run it directly.)
In the Windows Features window, Make sure ALL the NET Framework Features are turned ON.
Restart your PC
My TurboTax Deluxe updates all the time now.
