|Open a command prompt window on the vista PC and type the following commands:|
ipconfig /release [Enter]
ipconfig /renew [Enter]
and see if it can then access the internet afterwards.
If not, open a command prompt window on both the vista and the XP PC's and type the following command:
Compare the output. Everything should be identical except the IP address. If there are any differences, such as different DNS or Gateway address, that's the issue.