The "Options" button (Toolbar on the right) is available when you first login, prior to click on the posts.

>>In the options (your account settings) in the display mode, change it to "Ungrouped Treeview Mode"
>>
>
>Right, but I do not see a way to go to my Account settings. I already logged in and I'm seeing threads on the left and view of the message on the right. I do not see any buttons to go to Account settings.