Don't use XP then...

I'd still be using NT4 if it wasn't for the fact that Microsoft refused to give it USB support. Runs great on old hardware (the minimum spec was roughly 66MHz and 12MB RAM, 120MB HDD)

I'm sure the charities offering XP at a fiver a go can get hold of NT4 licences from somewhere (or talk Microsoft into offering downgrade rights), for developing ICT skills you don't need anything more really, can stick OpenOffice or MS Office onto an NT4 machine fine.