Yes, I'm aware of the win7 hiding them, I have mine (dragged to the notification area/tray) so it is always shown. I consider it essential even on my tiny win7 netbook, I also have my MBAM, WinPatrol and Firewall icons there.
Nothing to stop the avastUI being pinned to the taskbar another option.
OK, I have done some more rummaging, I have ObjectDock on my win7 netbook. I added a shortcut for avastUI.exe and that too works as expected, it opens the UI, I can close it with the X top right or Right click on the tasklbar item and select Close.
So no problem with ObjectDock, win7 and avastUI closing.