Upgrading to XP

[jaberwok]

Yes.
Stuff that used to get saved to the registry is now saved to the user profile.

[glee.94356]

Autocad 2004 is stable on XP pro sp2. I assume 2005 should be too. You do not need to disable the firewall. Your IT guy should know what to do. You can allow autocad to communicate with autodesk. Either in your base firewall configuration or whatever viruscan program you have installed. (It's just allowing the domain or the IP).
XP pro is similar to win 2000 pro (think NT 5 vs. NT 5.1). It just has that product activation thing that 2000 does not.
If you like the microsoft office task bar, you won't get it in the new office installation. XP is meant to be more streamline. It sort of learns what you use on a regular basis and puts it in your start menu, wants to clean your desktop if you don't use certain icons, etc.
It's a good thing you are getting new computers. Clean install is always better. Some older machines don't have sufficient memory or computing power to run XP pro. May want to check if you have older plotters or printers and see if there is support for their drivers on XP.
XP pro is easy to use for the most part and fairly easy to configure for networks. Mid size and small firms will find it fairly friendly. Small firms particularly who know a little about networking should be able to handle it on their own. 2-3 person firms can network the machines fairly well. Either peer to peer or with win 2000 server. Do not disable the firewall like some web sites will tell you. All you have to do is allow your LAN network or assign IP addresses and provide them to the firewall. Even if you have a hardware installed firewall on your router, I think it's a good idea to have many layers of redundant security since most networks are now on the internet 24/7 with broadband access. Your IT guys will know this. Besides on smaller networks many of them have not turned on the firewall or configured it correctly on their routers.
Anyway, win pro sp2 is not bad. Built on NT and brings all the issues that were corrected on 2000 to it. Just that product activation thing. It ties that particular installation to that particular machine. if you ever want to reinstall XP on that machine, it becomes a little painful. As long as your IT guys backs up the Wpa.dbl for that machine and ensures he knows which OS serial number he used, when he reinstalls, all he has to do is replace that file while in safe mode and everything should be fine. As long as the same OS and serial number is used on the same computer. This is not a hack, just a easier work around.
Ok. nuff said. Probably more than you wanted. I need to get a life.