My Book Live using my primary C: drive for storage

Its not a WD issue that’s a winDAV problem which makes it a windows limitation but from my experience the computer will show the same size as you primary hdd only when your connecting to the drive via wd2go if you map it manually and make sure its not using winDAV you’ll get the true sizes. You can still write the the my book live drive it doesn’t really take up space on your primary hdd its just thinks it the same size as your C drive. The second link may be a possible solution for you.

http://community.wd.com/t5/My-Book-Live/Swallowing-my-pride-and-asking-for-help/td-p/459536/highlight/true

http://community.wd.com/t5/My-Book-Live/WebDAV-Primer-Microsoft-vs-WD-My-Book-Live-etc/m-p/576975/highlight/true#M23535