Question about software registration (Adobe Photoshop)

I have the opportunity to buy a used copy of Adobe Photoshop CS at a good price, but ... the seller claimed he uninstalled it from his computer, and that it has never been registered.

I think that's not possible, because I'm under the impression that Adobe Photoshop can't be installed without registering it.

Someone I know, a computer guru who speaks many levels above my comprehension, said I can research whether it's been registered by asking the seller for the "part number." (Then the guru had to hurry to a project, and couldn't discuss it further.)

Is this true? If the seller gives me the part number, is there some online resource where I can enter the part number and learn its registration history?

Yes Photoshop has to registered to be used. If it's a legal copy of Photoshop it should have a registration number. The part number may be on the back of the jewel case. Ask this person how they used it without registering it.

I started out with Photoshop 2.0 (nine floppies worth!), and upgraded to 5.0 for only $100 by giving the registration number. When I tried to re-install my 5.0 recently, it wouldn't accept my 2.0 registration number. I suspected it was because the number was outdated, so I called Adobe. They asked for the number, then told me to put in the CD and click on the Photoshop eye. Much to my surprise, a menu box came up, they gave me a new registration number, and it installed perfectly!

:headbang:
rocknation