This might be a big thing to ask but ... Why not try an experiment & use his wireless device (you will prolly need to install the drivers & then enable it within the system & then enable UPnP), & connect thru his connection & without him using LW or another p2p program at the same time. See what happens. It might be a big favour to ask of him, but at least this will show whether the problem is on your system & its set up or something else. Also, try to temporarily disable McAffee firewall & have XP's firewall on instead, instructions for configuring XP's firewall: Firewall configuration instructions (click on link)

As suggested by FOTH, do the magnet test also.

BTW I hope you don't normally run with 2 firewalls running. And is your McAffee the full version or a trial version or ... ?
I've heard of people having McAffee problems before.

Ok, I turned McAfee off, Windows Firewall on, configured it, tried both UPnp, and port forwarding using the port it says it's listening on. Connected to his wireless (which is simple, because all I have to do is turn my wirelss on on my laptop and it automatically connects to it because he gave me the password), without his computer connected to the router, and yet I still only get speeds of about 7KB/s, whether I download from 1 host, or 10. I also ran the magnet test, and got the same results.

And no, I do not normally run with both firewalls running. And I'm not entirely sure if McAfee is a trial version or not, it came already installed on the computer.