I just chose to install Unity 2018.1 b11, and it seemed to download, and it created a folder in Program Files for b11, but the folder is empty except for the attached modules.json file..
So, I have my Editor Folder Location set to D:\Program Files\Unity, but Unity Hub installed b11 in C:\Program Files\Unity\2018.1.0b11.
Also, the sample project was installed in C:\Users\Public\Documents\Unity Projects. I'd prefer to be able to specify the location for these projects in my D:\ drive.