Snippet below can be used to programmatically determine if User Account Control is enabled:

objectpascal Download
uses
  JwaWinbase, JwaWinNt;

function IsUACEnabled: Boolean;
var
  hToken: THandle;
  tet: TOKEN_ELEVATION_TYPE;
  dwSize: DWORD;
begin
  Win32Check(OpenProcessToken(GetCurrentProcess, TOKEN_QUERY, hToken));
  // TokenElevationType class only available on Vista+
  Win32Check(GetTokenInformation(hToken, TokenElevationType, @tet, SizeOf(tet), dwSize));

  Result := tet <> TokenElevationTypeDefault;
end;