Avast is normally accessed via the little orange icon at the bottom right of your screen. It looks like this:
http://pluspng.com/img-png/avast-logo-png--170.png
(If you can't see it you might need to click on the 'Show hidden icons' button, which is a little white triangle, first).
I'm not sure where AdwCleaner will have gone to but you should be able to find it clicking the Start button and typing 'adwc' into the search box. When you've found it in the results section there,you can then right-click on it and select 'Pin to start menu' (and/or 'Pin to taskbar').
(I haven't got a clue about what Danny's doing. The file in his Downloads folder should be the setup file, which you only need to run once. Perhaps he might benefit from the advice in my previous paragraph?)