One day when I was trying to work with the Adobe Photoshop CS, it stop working when I run the program, it hangs on loading splash screen where it stated it was loading preferences…

Tried killing it with Task Manager, Reboot, all did not seems to work, so google is always the best solution!

I came across this forum from google about almost the same issue.
http://www.graphicdesignforum.com/forum/archive/index.php/t-5632.html

It turns out there is a key input combo, by holding down shift + ctrl + alt when Photoshop starts, this force Photoshop to clear and rebuild the preferences files which solve my problem.