Here are the steps to take, and the order in which to take them if you want to rename a server that has MOSS already installed and configured on it:
1.Change each alternate access mapping for your MOSS/WSS deployment in Central Administration:
-Open Central Administration, "Operations" Tab, "Alternate access mappings" link -Modify each mapping item to reflect your newly chosen server name
2.Use stsadm.exe to invoke the "renameserver" command option:
-Open a command prompt window
-cd "C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\BIN"
-stsadm -o renameserver -newservername
3.Rename your Server via Change Name Operation in Windows Server 2003: Start Menu Control Panel System, "Computer Name" tab, "Change" button.
4.Input your new server name
5.Reboot the server NOW.
6.After reboot, open command prompt
-cd C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\BIN -stsadm -o updatefarmcredentials -userlogin
7.Check all application pool identities in IIS, update where the old machine name is still there.
8.If you already have a search index drop this, and rebuild it.
Your server is now renamed.