Replying to I need help with pirating photoshop

ok, so i downloaded it on limewire. scanned it for viruses (its clean) and i entered in the serial number that came with it when i downloaded it.

now it has this message that says:

please choose if you want to register your adobe product now.

and it has some choices:

-register online

-print out and mail

-do not display this dialog again

im gessing you dnt register which is the ovious answer. but i dnt know waty registering is and if i dnt do it want happens