Did you try this ??
delete filespace WINNODE \\WINNODE\e$

I have not seen this choice in you list.
There is problem with filespace naming sometimes, I had similar problem a
few months ago, and only way was clicked through WEB admin to particular
filespace and chioce Delete filespace in Operation tab, than the name of
filespace in delete command is fulfiled automatically.

With Best Regards
Tom