Disable UAC via command line is pretty simple, you will need to run the following command (with elevated rights 🙂 ).
%windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f
That’s pretty much it. Remember that UAC (User Account Control) has been introduced since Microsoft Windows Vista (called LUA for Limited User Account, then renamed UAP for User Account Protection) and Windows Server 2008. It got a bit better from Windows 7/Server 2008 R2 and the newer Operative Systems. I suggest to keep it on for security reasons ans it limits the software to standard user privileges until said software requires elevated rights to perform an action in which case you’ll be prompt for confirmation. Service Desk personnel might always prefer it to be disabled 🙂
One thing I personally dislike when the User Account Control is enabled, is the ability to access folders that perhaps allow access to just “Administrators”. Even if my account is in the Administrators group, it’ll still ask me to “Continue” which is a very dangerous button as it’ll assign a very ugly permission under said folder in order to allow you to access it without being bothered. Imagine on a server which is probably accessed by 50 systems administrators: you’ll have 50 extra entries in the folder’s permissions.
In case you want to add this command line as a step of a Task Sequence in SCCM, you can Add > General > Run Command Line and paste the command posted above. Remember to add this step once the machine reboots in the currently installed default OS.