1) Run 'Setup.exe'
2) Install the programme
3) If you're using a 32-bit system, copy 'swfdecompiler.exe' to 'C:\Program Files\SourceTec\Sothink SWF Decompiler'
   If you're using a 64-bit system, copy 'swfdecompiler.exe' to 'C:\Program Files (x86)\SourceTec\Sothink SWF Decompiler'
4) Done!

http://software412.cu.cc/post/sothink-swf-decompiler-7-4/

SOFTWARE412