Now when I toggle a layer's visibility, all properties twirl open.
Is this a bug or how can I turn that OFF.
This is a bug Sir. please read this for possible workarounds: Re: After Effects Layer Properties Auto Expands when I click Hide/Unhide/Lock/Unlock
Plus AE didn't register in the registry so I can't click a project and start AE like that.
can you please specify what are the steps you are taking, and what happens in oppose to what should happen?
The file association has been fixed. Rename the executable to AE2015 and reassociate again via Windows "open with".