Pool Nonpaged Bytes is the size, in bytes, of the nonpaged pool, an area of the system virtual memory that is used for objects ...

Pool Nonpaged Bytes is the size, in bytes, of the nonpaged pool, an area of the system virtual memory that is used for objects that cannot be written to disk, but must remain in physical memory as long as they are allocated.  Memory\\Pool Nonpaged Bytes is calculated differently than Process\\Pool Nonpaged Bytes, so it might not equal Process(_Total)\\Pool Nonpaged Bytes.  This counter displays the last observed value only; it is not an average.