Need Help

[Trigz]

Photoshop Cs5.1:

I have a big problem with PS. So let me start off buy saying that when I load it up, It says I have 0 days left for the trial, and that I could enter a Serial Number. I click on it, putting my Serial Number then the Photoshop works, while working a minute later it says that the Serial Number is incorrect, but I could still use PS. When I shut down the app and later I reopen it....It wants me to put up another Serial Number WTF?

[suiko]

You could just delete it and download it free online
thats what i did lol