How much memory does Windows support?

I had a customer recently ask about the memory limits for various editions of Windows, and thought that I would share the answer with everyone (as it took me a little while to find it). As 64-bit drivers are becoming more common from the OEMs, it is more and more tempting to use 64-bit editions of Windows (I just switched from 32-bit to 64-bit on my work computer, and have not yet run into any incompatibilities) J

https://msdn2.microsoft.com/en-gb/library/aa366778.aspx

Physical memory limits

32-bit Windows

64-bit Windows

Windows Server "Longhorn", Datacenter Edition

128 GB

1 TB

 

64 GB with 4GT RAM Tuning

  

Windows Server "Longhorn", Enterprise Edition

64 GB

1 TB

Windows Server "Longhorn", Standard Edition

4 GB

32 GB

Windows Server "Longhorn", Datacenter Edition (Server Core installation)

128 GB

1 TB

Windows Server "Longhorn", Enterprise Edition (Server Core installation)

64 GB

1 TB

Windows Server "Longhorn", Standard Edition (Server Core installation)

4 GB

32GB

Windows Vista Ultimate

4 GB

128 GB

Windows Vista Enterprise

4 GB

128 GB

Windows Vista Business

4 GB

128 GB

Windows Vista Home Premium

4 GB

16 GB

Windows Vista Home Basic

4 GB

8 GB

Windows Vista Starter

1 GB

N/A

Windows Storage Server 2003, Enterprise Edition

8 GB

N/A

Windows Storage Server 2003

4 GB

N/A

Windows Server 2003, Datacenter Edition SP1

128 GB

1 TB

 

16 GB with /3GB

  

Windows Server 2003, Enterprise Edition SP1

64 GB

1 TB

 

16 GB with /3GB

  

Windows Server 2003, Standard Edition SP1

4 GB

32 GB