n Virtual addresses (p1, p2, d) use 32 bits where p1 and p2 are each 10 bits wide u p1 selects an entry in the page directory which points to a page table u p2 selects an entry in this page table which points to the selected page n Upon creation, NT commits only a certain number of virtual pages to a process and reserves a certain number of other pages for future needs n Hence, a group of bits in each PTE indicates if the corresponding page is committed, reserved or not used