I have purchased a used ps2, which came with a network adaptor, however no instructins or as I have read to learn, THE DISC, how can I obtain one? THanks

I've just scoured the net for an answer for you, and it seems I've been hit with a 'duh' moment.

Anyway, found an answer for you that is sooo obvious it's ridiculous.

First a question to you. Do you have any online capable games? If so then that's your problem solved.

Just go to Online Play (or whatever the option to play online is called on that particular games) and there will be an option on the next screen that will let you "Create a New Network Configuration".
Then it's just a matter of answering some simple questions (most of it can be done automatically without having to actually type anything in) and then a NEW Network Configuration file will be saved to your PS2 Memory Card.
That file can then be used on any Online Capable PS2 games to, well, get online with.

The only thing different about the Sony Network Disk, apparently, is that it lets you register with Sony. However, you can register with them via the telephone or online, so it's not really needed.

Hope that helped,
Jay

Sony Network discs can be obtained from E-bay, just make sure it's a new one with an unused code.

You Need to Have The Network Access Disc I Have Tried With All My Online Capable Games And It Says That You Need The Network Acces Disc

I can get online with a Star Wars disc but when I try with COD3 it comes up with DNHP error,(cable not connected). Any idea why?

You don't have to obtain Network Acces Disc. You can also make your network setting with PES. Select the "Network" in Menu and apply to directives.