I would like to set a PPP tunnel between an XP machine and a Linux
machine.

I am looking for something very low overhead:

Currently Unix-to-Unix works as:

host1#pppd updetach noauth passive notty ipparam vpn 10.0.0.1:10.0.0.2
host2#pppd nodetach notty noauth

It does what I need - a new interface that allows me to connect

I tried setting up a VPN connection from within windows, but most I
managed to do - disable encryption.

What should I do?