When I try to install Beta 1, it just stops at the point where I click Install. (The image below, doesn't show the little waiting wheel of doom!)
Other info: Machine using Windows 7, first time I've attempted 19.1. Installing as my self, but I am an administrator.
Note: As an aside, if you look closely at the text in the orange header, the word 'installation' is truncated. Also, the text could look 'tidier' and more contemporary, if the control names are highlighted using bold rather than "", i.e., Click Install, rather than Click "Install".