ImportError: DLL load failed: The specified module could not be found.
To get round this you need to install an older version of python. On top of that you need GTK with glade (which for some reason doesn't always seem to be included) - if you're getting errors about a missing libglade-2.0-0.dll then you've only got plain GTK without the glade. The exact files which worked for me are:
aqsis-setup-1.6.0 - for preview rendering
Just unzip Sler to a clean folder then inside the bin subfolder create a new batch file with something like the following to set your path and start sler:
set PATH=C:\Program Files\GTK2-Runtime\bin;C:\Python25;C:\Program Files\GTK2-Runtime\lib;C:\Program Files\GTK2-Runtime\;C:\Program Files\Aqsis;C:\Program Files\Aqsis\bin
@set GTK2R_PREFIX=G:\Program Files\GTK2-Runtime\bin
@echo set PATH=%GTK2R_PREFIX%;%%PATH%%
Best of luck, let me know if you have any problems.