gords edit: Wow, still spamming? Poor form indeed.
Yes just move to Windows 2008 server and use acronis
Removed windows XP from the server computer.
And then install and run a domain controller Eg (Windows Server 2003 or 2008) and then deploy...
Sounds like your talking about DNS TTL (Time to live) or your talking about the DHCP server lease time
Which one is is?
You will of course need a gigabit network card in your computer/s for this to work as it will cause a bottle neck....No point in having a gigabit...
(Agg edit: if you'd like to advertise on OCAU, please contact email@example.com for info.. ta)
I would suggest you check out Sonic Walls
Its a great hardware firewall so will do everything that you need!
What ISP are you with.
They should be able to provide you with support for this and figure it out with no fuss if they are any good.