I downloaded the full ISO for Visual Studio Ultimate CTP 6. The installation program got to about the 90% mark, gauging by the progress bar, and just stuck there. There wa
If you are using windows 10, "Windows defender" might be the reason for blocking. mine is hang while installing "Java SE development"
To disable windows defender during the installation phase:
Open Windows Defender by clicking the Start button Picture of the Start button. In the search box, type Defender, and then, in the list of results, click Windows Defender.
Click Settings, and turn off Real-time protection.