Windows RAM Support

Here’s a list of how much RAM the various Windows versions and editions support (as of Nov 2004):

Windows NT 4.0: 4 GB
Windows 2000 Professional: 4 GB
Windows 2000 Standard Server: 4 GB
Windows 2000 Advanced Server: 8GB
Windows 2000 Datacenter Server: 32GB
Windows XP Professional: 4 GB
Windows Server 2003 Web Edition: 2 GB
Windows Server 2003 Standard Edition: 4 GB
Windows Server 2003 Enterprise Edition: 32 GB
Windows Server 2003 Datacenter Edition: 64 GB

From http://support.microsoft.com/kb/555223