2- In Win 2000 server we can apply 620 group policies but in 2003 we can apply nearly 720 so Win2003 server is more secure than win 2000 server.
3- In 2000 we cannot rename domain whereas in 2003 we can rename Domain.
4- In 2000 it supports of 8 processors and 64 GB RAM (In 2000 Advance Server) whereas in 2003 supports up to 64 processors and max of 512GB RAM.
5- Win 2000 Supports IIS 5.0 and 2003 Supports IIS6.0
6- Win 2000 doesn’t support Dot net whereas 2003 Supports Microsoft .NET 2.0
7- Win 2000 has Server and Advance Server editions whereas 2003 has Standard, Enterprise, Datacenter and Web server Editions.
8- Win 2000 doesn’t have any 64 bit server operating system whereas 2003 has 64 bit server operating systems (Windows Server 2003 X64 Std and Enterprise Edition)
9- Win 2000 has basic concept of DFS (Distributed File systems) with defined roots whereas Win 2003 has Enhanced DFS support with multiple roots.
10- In 2000 there is complexity in administering Complex networks whereas 2003 is easy administration in all & Complex networks.
11- In 2000 we can create 1 million users and in 2003 we can create 1 billion users.
12- In 2003 we have concept of Volume shadow copy service which is used to create hard disk snap shot which is used in Disaster recovery and 2000 doesn’t have this service.
13- In 2000 we don’t have end user policy management, whereas in 2003 we have a End user policy management which is done in GPMC (Group policy management console).
14- In 2000 we have cross domain trust relation ship and 2003 we have Cross forest trust elationship.
15- Win 2000 Supports 4-node clustering and 2003 supports 8-node clustering.
16- Win 2003 has High HCL Support (Hardware Compatibility List) issued by Microsoft.
17- Code name of 2000 is Win NT 5.0 and Code name of 2003 is Win NT 5.1
18-Win 2003 has service called ADFS (Active Directory Federation Services) which is used to communicate between branches with safe authentication.
19- In 2003 their is improved storage management using service File Server Resource Manager (FSRM).
20- Win 2003 has service called Windows Share point Services (It is an integrated portfolio of collaboration and communication services designed to connect people, information, processes, and systems both within and beyond the organizational firewall).
21- Win 2003 has Improved Print management compared to 2000 server.
22- Win 2003 has telnet sessions available.
23- Win 2000 supports IPV4 whereas 2003 supports IPV4 and IPV6.