Generally speaking, there is no function difference between both versions. For some of the products such as Sothink SWF Decompiler, Sothink DHMLMenu and SWF to Video Converter etc., there do exists certain restrictions to the functions of the unregistered version; you can refer to the very product page to see the difference. The unregistered version is for evaluation purpose only. And it is limited to be used in 15 ~ 30 days since the installation of the program. When the evaluation period expires, you can not use the program any longer. To know more limitations of unregistered version for different software, please go to see different products’ webpage.