Hi John,
Adobe Creative Cloud should install on that system without any issues at all.
What error(s) are they seeing when trying to install Avast and Adobe CC - please provide the specific error(s)
There is one thing that might be stopping then installing 3rd party applications:
Open the Settings App
Go to System - About
Check the Windows Edition, are they running Windows 10 S
Windows 10 S can only be user to install Windows Store apps, they need to swap over to Windows 10 Pro