I have no problem with a system like Harry's that is never connected to the Internet. Except that I don't think XP is a very good file server.

Especially if all the rest of your systems are Win7/8 or Server 2012. Because now you're forcing me to use _old_ file protocols (SMB 1.0 packets).
And you're right,
Glorfindel, I didn't call out "Zero Day, Every Day", though that was certainly in line with my final comment about not having to worry about Patch Tuesday any more.