UAC: to disbale or not?

I have read in official documentation and tech notes/this forum/etc. about the need to disable UAC. The Install Guide has that requirement only under the server install section but no mention of UAC under the client install section.

So my question is: Is it required to disable UAC on Windows servers when installing/upgrading NetBackup client?

As documentation does not indicate that disabling UAC is mandatory for client installs - why does the install script warn the user to disable it?

PS: Install guide only mentions that the account needs access to write to C:\Program Files\ only.

Environment: Master/Media on Linux with NBU 7.6 and clients are Windows 2008/2008 R2/2012 regarding UAC