supposedly. However, Servers nowadays have redundant everything (memory, HD's (RAID), power supplies, network cards, etc), so they're able to run pretty much non-stop. 

I don't know on a code level, but I think the Server OS is mainly the Workstation OS with more bells, whistles, processes, 'snap-in's', etc. (Of course, Windows Server 2003 is out standing in it's field..;)

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)