Thank you David,
I have got the image of Debian-8.10. As to Debian 9 (Stretch) per Chris' concern, I believe the main problem is the KDE 5 GUI that it used. There had been lots of bugs reported. When I upgraded to Debian 9 from "Jessie", all my KDE 4 GUI were messed. Also, the KDE 5 is more like Windows GUI, which is not satisfactory, especially the SDDM. The new SDDM listed all the users in the LOGIN page, as in the Windows LOGIN. This reveals the information of all the users of the platform, which is a security issue. In the old KDM LOGIN, we can choose to key in username and password separately, which is more secured, from my personal view.