Urgent, system preference got frozen and not not working.

I was trying to change the desktop picture and after I chagned, I did not like the picture and wanted to choose another one, I went back to system reference and open the desktop and screen saver, It started to show a circle with rainbow color and cannot close or do anything, I forced to quick and send the report to Mac, and re start again. but I still cannot do anything with system preference, they go back to desktop screen saver screen and cannot do anything, please let me know what I did wrong and what I need to fix this!

thank you very much.