Is that the IP address from the XP machine? That's an external IP address, like one that is handed out to a router. I forget, you do have a wireless router, right? What kind, or is the modem the router?
Well the problem is you're going out on the internet then trying to come back in. The Insight router is handing out external IP's. Either the port on Dell's firewall must be opened, or the port on the router must be directed to the Dell. Unless you have a very secure password I would be careful of either. Since you can't even get to the router there's nothing I can do without knowing what kind. Then you'd have to know the password to get into it to forward the port to the Dell.
How do you connect with the Touch, is it an IP of 74.x.x.x? Don't post it, only the first set or two of digits.
Did you set the firewall in XP like in the directions of the first link I posted? If so then the problem is in the router/modem or whatever it is, it would need to be set. Again, if you can't get at it or configure it there's nothing we can do.
I need to know exactly what is on the chain to the Dell, and to your touch. Modem to router? What is doing the wireless, what kind of modem, router etc, and do you have access to change settings on them. If you don't there's nothing we can do. I don't know why you can go the other way either, to the touch from the Dell, without knowing how both of you connect.
Can you do a network ping to the Dell like I asked you to try?
Then you either have the wrong IP or something is blocking traffic to the Dell.
Is it the IP in the image above? I can't ping it either. Don't post your IP in text format BTW, the picture was kind of okay. It's not a good idea to put it out in the open though.