File/Print sharing mysteriously not working??

I'm at a collegues house last night setting up a new laptop for his daughter. They have SBC DSL with the 2-Wire home portal. When I had my laptop on his network (wireless), it worked fine. I could share files/printers from my laptop to their existing PC. This new laptop seems to be having hissy fit about it.

Laptop to existing PC comes back ACCESS DENIED when you just punch in //[computer name or IP] and none of the shared folders or printers show up.

In the home portal LAN setup, you have that link to open the shared files/printers from the configuaration screen. I can open the existing PC's resources from the router but I get the same guest login if I try the laptop.

Existing PC to the laptop brings up a login screen for the guest account. I don't want to have to do that, I want it to just see the damn shared resources and be done with it. I tried everything i know of. NetBIOS is on, file/print shares are set. Windows firewall is off. What the hell else is there? This is all Windows XP Home.

 

Log to this page it has a lot of links to instructions to Windows Network Settings, and Sharing.

Link to: Windows Network - Installing & Sharing.