Is there any way to retrieve the available disk space from within a WinJS application?
I've found information on creating windows runtime components, and then including those in your application, but it doesn't look like System.IO.DriveInfo is supported.
Supported methods:
http://msdn.microsoft.com/en-us/library/windows/apps/hh454050.aspx
How to create a Windows Runtime Component:
http://msdn.microsoft.com/en-us/library/windows/apps/hh779077.aspx