Error 13 means: "The data is invalid." Are you sure that the key contains REG_SZ or REG_MULTI_SZ element named "Element" that points to proper GUID? Check this with bcdedit too.
I see the one possible solution - "bootrec /rebuildbcd"... see http://pcsupport.about.com/od/fixtheproblem/ht/rebuild-bcd-store-windows.htm be careful!
HTH