In Sweet Home 3D 5.5 released last week, I added the 3 following options to Windows installer to let you choose the Java 3D version and architecture used by the program when there are some problems:
[font=courier new]/os.arch=x86[/font] will force the installation of the 32 bit version of Sweet Home 3D under Windows 64 bit
[font=courier new]/j3d.version=1.5.2[/font] will force the installation of Java 3D 1.5.2 (default Java 3D version until Windows 7)
[font=courier new]/j3d.version=1.6[/font] will force the installation of Java 3D 1.6 (default Java 3D version from Windows 8)

To use these options, simply execute the installer in a cmd window followed by the options of your choice separated by spaces. For example: For people not used to commands, this can be achieved this way:
- Press <Windows> + R keys
- Type [font=courier new]cmd[/font] and press <enter> key
- Drag and drop the icon of the installer [font=courier new]SweetHome3D-5.5-windows.exe[/font] in the command window
- Type a space in the cmd window
- Copy [font=courier new]/os.arch=x86 /j3d.version=1.5.2[/font] and paste it in the cmd window
- Press <enter> key.

From you last comments, using Java 3D 1.5.2 after updating your graphics driver might be enough to run Sweet Home 3D under Windows 64 bit, in which case you could first try to run the installer with the option [font=courier new]/j3d.version=1.5.2[/font]

I'm looking forward to reading your comments to be able to modify the FAQ accordingly.