I'm a linux user but, your path is not OK for WINDOWS.
SH3D, under WINDOWS have the working path at:

C:\Users\User\Application Data\eTeks\Sweet Home 3D

Under this folder you have some other folders:
-furniture
-languages
-plugins
-recovery
-textures
-work
and the preferences file.
Navigate on this path (don't ask me how to do under WINDOWS) and delete work & recovery folders.
Usually it appears only when you open an existing .sh3d file.
Don't worry, will be recreated when needed.
Probably this could solve your problem.
Good luck!