Available MBytes is the amount of physical memory, in Megabytes, immediately available for allocation to a process or for ...

Available MBytes is the amount of physical memory, in Megabytes, immediately available for allocation to a process or for system use. It is equal to the sum of memory assigned to the standby (cached), free and zero page lists. For a full explanation of the memory manager, refer to MSDN and/or the System Performance and Troubleshooting Guide chapter in the Windows Server 2003 Resource Kit.