Try resetting the XP tcpip stack.
netsh int ip reset [log_file_name]
To run the command successfully, you must specify a file name for the log where actions that are taken by netsh will be recorded. For example, at a command prompt, type either of the samples that are listed in the "Command samples" section. The TCP/IP stack will then be reset on a system, and the actions that were taken will be recorded in the log file, Resetlog.txt. The first sample creates the log file in the current directory, while the second sample creates a path where the log will reside. In either case, where the specified log file already exists, the new log will be appended to the end of the existing file.
netsh int ip reset resetlog.txt
netsh int ip reset c:\resetlog.txt