Hans download this file which has default settings
http://www.mediafire.com/?9vmlx54x3zv90nh
Then copy, paste to the location "C:\Program Files\Sweet Home 3D\SweetHome3D.exe" or the location where the "SweetHome3D.exe" located.
&
Here is the description for the commands
http://www.mediafire.com/?1hbx7495ki2iu7y

Edit the values or delete the lines if you want to customize.
Then save SweetHome3D.l4j.ini & start application "SweetHome3D.exe"

Improper or null value makes application crash then delete SweetHome3D.l4j.ini from the directory

To see Available Graphics memory Go to Win > Start > Run (or press Win-key+R),then type "DxDiag" & click display tab > Total memory=
Memory Values must be a multiple of 32.

Here is the file I uses to Exterior rendering
http://www.mediafire.com/?76y5jukvyqthgkl

Sorry for my bad .English.
[:)>-] [\:D/]