As Blue Screens of Death go, PAGE FAULT IN NONPAGED AREA is as close as Windows comes to saying “invalid memory reference.” To really understand what’s going on, one needs to understand that paged memory divides addressable memory space up into a collection of 4K-sized memory pages. The OS can address a very large number of pages, where only some of those pages will actually be resident in RAM. The more RAM installed on a PC, the more likely it is that any given memory page will be resident therein.
In most cases, when a program or the OS references some specific memory page, it attempts to access that page. If it’s resident in RAM, it goes straight there. If it’s not resident, the page manager throws a “page fault” (page not present) status. Ultimately, this means the requested page gets read from the page file and gets moved into RAM. To make room for something new if such room is needed, an old memory page (one that hasn’t been accessed recently) will be written out into the page file to make room for an incoming page from that same source. This is called a “page swap.”
