Give a more details as to your goal.
If you want to login and use the command like, consider OpenSSH server. The benefit here is that it also alows you to sftp, ftp over SSH. Use Putty on your xp box to connect to it.
If you want to browse shares like a Windows Network, install Samba. It takes a little tinkering to get a user, password and shares created. It is not something you want to make avaiable across the Internet.
If that is the case, look into SSH.