• Windows 2000 Professional:
  
  
  Windows 2000 Professional is a desktop operating system that incorporates the best business features of Microsoft Windows 98 and builds on the traditional strengths of Windows NT 4.0. It supports SMP systems with 2 processors and 4 GB of physical memory.
  
  
  
• Windows 2000 Server:
  
  
  Windows 2000 Server is the standard edition of the server family. It contains all the features of the Professional version and is ideal for small to medium sized organizations. This version of Windows 2000 works well for file and print servers, Web servers, and workgroups. It supports SMP systems with 4 processors and 4 GB of physical memory.
  
  
  
• Windows 2000 Avanced Server:
  
  
  Windows 2000 Advanced Server contains all of the functionality of Windows 2000 Server, plus increased scalability and system availability. Scalability is the ability to increase processing power incrementally to meet increased nework demands. This functionality is provided through clusters of multiple servers. It supports SMP systems with 8 processors and 8 GB of physical memory.
  
  
  
• Windows 2000 Datacenter Server:
  
  
  Windows 2000 Datacenter Server contains all of the functionality of Windows 2000 Advanced Server, plus support for additional memory and CPUs per computer. It is designed for large warehouses, online transaction processing, and large-scale simulations. It can also support more than 10,000 simultaneous users in certain workloads. It supports SMP systems with 32 processors and 64 GB of physical memory.
  
  
  

WINNT32 /checkupgradeonly
chkupgrd.exe - available online.