The device you're using as a server must have Samba v1 enabled. In your case, the router doesn't have it, so there's no point in leaving the memory connected to it. If you have another router that you intend to use as a server, you'd have to start over.
We're going to take advantage of the auto MDI (Media Dependent Interface)/MDIX (Media Dependent Interface Crossover) technology based on automatic negotiation, which is already present in most devices. This allows for a point-to-point LAN connection regardless of the type of Ethernet cable you're using. In the past, a crossover network cable was necessary for this type of connection, but now it's no longer required, and you don't need an intermediary like the router.
So we can connect the PS2 directly to the PC without any problems (I assume you already did this when you pinged it, right?). Naturally, using a P2P connection will be more efficient.
With that said, let's begin:
The first thing you need to do is disable version 1 of the Samba protocol on your machine, as we'll be using a program later that will facilitate the connection without leaving your computer vulnerable. To do this, you must disable the options you enabled for Samba version 1 in Windows.
Let me know when you've done that.