Cheapest place to get XP Professional?

you will need a separate windows license for each computer , it's ALWAYS been that way

if the computers already have an XP COA then all you need is the CD



If they don't then you need a new license

you cant use an OEM license since it's bound to the machine it was originally supplied with / isn't allowed to be installed on a machine that already has windows

you can only use an upgrade license if it hasn't been used already and your machine has a valid upgradable license already. ( you can use a license that has already been upgraded from a non-oem product, but rare as hen's teeth )

Microsoft stopped selling XP a long time ago and even then it was mostly for preinstalled netbooks , so you are looking at a second handcopy - and it's buyer beware since most legit copies were hovered up by people who hated vista

That's the rules microsoft set, because they make more money selling a new OS and they don't have to spend money supporting it when it goes end of life,

ebay / advets.ie

compare the cost for the windows 7 3 pack if still available
also what is the spec of the machines*?