To resolve this issue, determine the hardware device(s) on the Microsoft Windows Server Host OS reserving the memory. Other hardware devices attached to the system that reserve memory will result in lowering the total allocated memory to the Microsoft Windows Server host operating system.
For guidance on determining where memory is being allocated within the Microsoft Windows Server host operating system, see the Microsoft Knowledge Base article
978610.
Note: The preceding link was correct as of August 01, 2019. If you find the link is broken, provide feedback and a VMware employee will update the link.Though the Knowledge Base article is specific for Microsoft Windows 7, this is applicable to the Windows Server.
If this does not resolve your issue, engage your hardware or operating system vendor.