Photoshop not working

Try this:
1) Close Photoshop (if it's open).
2) Double click on the Photoshop icon to launch it
3) QUICKLY hold down Ctrl+Alt+Shift. (for Windows) or CTL+OPT+CMD+Shift (for Mac OS X)
4) When a dialogue appears, asking you “Delete Photoshop Preference Files?” Click Yes.
If you don't see the question repeat the procedure again.

What serial number do you mean?

I can only see the serial for my MAC

If you look at the screenshots you will se that Photoshop is not even starting so that is the problem.

"Not working" is not much help, can you explain what hapens in more detail.

Have you tried resetting the Photoshop preferences?

I suggest you delete the screen grab of your serial number on this public forum (or blur it).