I am about to upgrade our current Win2k server to a new server running Windows Server 2008 R2. Right now, our current server acts as our DHCP server, DC, and controls ActiveDirectory, amongst other things. Is there an easy (or not so easy) way I can migrate the current settings to the new server without having to set everything up from scratch?
Yeah. Add the new server to your domain, promote it, move the FSMO roles to it, run some AD diagnostics and check your event logs to make sure nothing bad happened. Leave it that way for a few days.
Then, move DHCP to the new server, and change all your client configs (via DHCP and manually for static IPs) to use the new server for DNS. Couple days, make sure nothing bad happens.
Demote the original server but do not turn it off or retire it. This way, you have kept yourself from having to redo your whole domain. But now you have to find every remaining client-facing service it provided, and figure out how to migrate them to the new one and how to reconfigure the clients.
Fileshares - if it's just a few, it's probably an easy overnight copy and fix some login scripts (or GPPs although prob not on a Win2k domain). If you're using manual mappings, well, that's why you don't do that, because now you've got a lot of manual work. The MS FileShare Migration Toolkit may help, or maybe not.
Printer mappings - the same but without the copying part. Just share the printers from the new server and start fixing the clients.
What else is on the server? IIS, BTrieve databases, SharePoint? As I said, you will need to identify each and every client-facing service and come up with a migration plan for each and every one. Migrate to new server, and fix the clients. Rinse and repeat.
Lastly - take 2 full backups, onto two separate tapes, and keep them safe. Preferably at least one off-site. Turn off the old server, or even just unplug it from the LAN, and leave it there for two weeks to see what you missed. Keep those tapes forever.