The only way to remote into XP Home (without installing a remote server) is through a remote assistance request.

Basically someone sitting at the XP home machine sends you a request via email or MSN messenger and then they can give you control of the machine and then you can connect to it with Remote Desktop.

You can also try Real VNC (http://www.realvnc.com/">http://www.realvnc.com) or Gooer as suggested above.