Re: First, identify the constraint
"There is no reason, other than bribes from MS, that the NHS shouldn't do the same, again with the exception of the specialist custom programs for the expensive equipment which should be on its own network anyway."
I was just in an NHS hospital. The standard PC doesn't run XP. It's the non-standard ones linked to MRI machines and other networks that have XP. Anything that wants that MRI image needs to be on the same network, as you aren't easily transmitting 500GB of data a time through an air gap.