I have the same computer as your friend. The built in driver works very poorly.
What I did to get the wireless working is this:
1) install ndiswrapper:
sudo apt-get install ndiswrapper-utils
sudo apt-get install ndiswrapper-common
2) get the correct windows XP drivers based on your system architecture (32-bit vs. 64-bit)
If you can't find them (it took me a loooong time to find them), I've attached them (at the bottom of this post).
3) Put all the files together in a folder (or just extract the folder matching the architecture I attached)
4) Disable the driver that doesn't work (the one that came with Ubuntu):
5) Use the graphical interface with ndiswrapper to install the driver. Or use the command:
note: "path to inf file" should be replaced by the actual path to the .inf file in the folder
sudo ndiswrapper -i "path to inf file"
6) It should now be installed. Activate ndiswrapper:
sudo modprobe ndiswrapper
7) Wait a while (~1 minute). Then check the network box at the top -- you should be able to find a network.
8) If it works, then permanently disable any other drivers that would interfere:
at the bottom copy and paste the following to the file:
sudo gedit /etc/modprobe.d/blacklist (if you are using Ubuntu)
sudo kate /etc/modprobe.d/blacklist (if you are using Kubuntu)
(note: this step was adapted from diepruis's guide that I could not get to work here: http://ubuntuforums.org/showthread.php?t=400236)
# Blacklist rt73usb
# Blacklist rt2570, as it causes conflicts with rt73
# Other modules that break rt73
9) Make sure ndiswrapper starts at boot: a good guide can be found here: https://help.ubuntu.com/community/Wi...0at%20start-up