OK, please bear with me: I'm not a newbie and not ignorant of basic Windows parameters but neither do I consider myself an expert - hence seeking your generous help!

I am running as TESTADMIN, an account which is a member of the Administrators group on a Windows 10 x64 Nov update machine. This was a clean install, not an upgrade.

I have installed an application (Quickbooks Premier 2016) as TESTADMIN. Everything generally works fine but there is one component (which I have to use) which needs UAC permission to activate. That component starts a service that allows sharing of files across the network. Once that service is started, the application seeks UAC permissions to open. Despite them being granted, the application fails to load. The service however, loads fine and indeed does successfully allow the files to be shared across the network with other installations.

If I activate the hidden ADMINISTRATOR account and run the program from within that account then I have no problem whatsoever. I have tried downgrading the UAC rights of the TESTADMIN account but no luck.

The service, the files accessed and the program files all have permissions that give read/write access to TESTADMIN. I can see nothing that TESTADMIN does not have permission to access.

My understanding was that the ADMINISTRATOR account differed from TESTADMIN only by it's degree of UAC control. But clearly there is something else the ADMINISTRATOR can do that TESTADMIN cannot. How can I found out what it is and thereby begin the process of increasing permissions?