After being asked if I would like to buy it or try it, I chose try. Then I was prompted to enter my adobe id and password. Once I do this the window gets a grey tint( I can still read everything). It stays this way with a small loading wheel in the lower right corner. The only thing I can do is minimize the wndow. This happens with Illustrator as well as Photoshop.
This behavior does sound like there is some type of security software installed. You can however initiate a direct download of the trial by following the steps listed at https://zerowing.corp.adobe.com/pages/viewpage.action?pageId=673972739.