"INVALID PAGE FAULT IN NON-PAGEABLE AREA" What's the tech-SD on this?

Factual Questions
1

(actual phrase may be incorrect. Paraphrased from memory)
My step-dad’s laptop just ‘died’ of this. (I had to use the recovery CD, which took hours to complete)

I’ve experienced this before, on a work computer.

Having experienced it twice (and both times the ‘help’ gave no clue as to it’s cause) I am wondering what the straight dope is from tech dopers.

When it happened on the work computer, the tech I informed had to re-ghost the HD image. (I assume that when removing all tech-speak from this phrase, it meant “copy a known safe ‘image’ of the virtual hard disk onto the physical hard disk”)

2

There is really no way to know, probably ever. Invalid page faults are an error that occurs deep within Windows sometimes due to a software conflict. They are given with a popup that also gives some level level system dump information that is almost impossible to interpret by someone that didn’t write that part of the software.

Just take it as an “Unknown Error, things are screwed up deep down” kind of thing.

3

Sounds like it could cause a crash but surprises me it would kill the computer.

Windows uses virtual memory. Instead of memory just being limited to physical memory, it also sets up some disk space. When there is some stuff in memory that hasn’t been used for a while it copies it out to disk to save it, use the part of memory where it came from, and copy it back if it needs it later. This allows the effective memory size to be much larger, though not nearly as fast as physical memory. The chunks it copies back and forth are in units of pages. Each time a program references a location in memory that isn’t there at the moment because it’s been copied to disk, that’s a page fault.

It may be that a bug caused a page to be written to a place on the disk that it is not really supposed to write to. I’m not sure precisely what that error message means in the context of Windows, though.

(You’re right about ghosting. I think the term comes from Norton Ghost, although it could be the other way around.)

4

Much of this is simplified and not exact, and forgive me if you know this already.

Memory is where the computer juggles. Data needed by programs (including the operating system) is kept in memory, which provides high speed access. Memory is allocated to programs in chunks called “pages”.

As more and more areas are allocated to programs, it is possible for the system to run out of allocatable chunks. When this happens, the operating system goes through the pages and frees up pages that haven’t been used recently. (the exact method of identifying candidate pages varies). Some of these freed up pages come from programs that have been closed or finished, some from programs are idle (the data for these is migrated from memory to swap space on a disk). The pages are left in memory because there is no reason to free them until they are needed. Leaving them be improves resource utilization.

So, pageable memory is memory that has been allocated to a program or process but is eligible for reassignment to other processes.

Non-pageable memory is memory that has been assigned to a program or process that should can not be re-assigned. It should be left allocated. Pages assigned to the system’s kernel are a good example. Want to keep those close at hand and readily available.

Now we get to the goodness. Programs or processes request memory pages. The system keeps track of what memory is allocated where and programs or processes are notified of their pages.

Somehow, in this case, the system, kernel, program, process or something tried to free up the wrong page. It tried to free up a page that was marked as non-pageable (must remain resident in memory). At this point, the kernel doesn’t know how to resolve the issue.

Rather than take the chance of making a mistake that could put the system or program into an unknown state, the kernel stops what it’s doing and tells the user (or panics and halts).

Some process on his laptop (and your work computer) caused the kernel of your operating system to lose track of what it was doing and it did the only sensible thing it knew: stopped and told you.

Now, I don’t understand why you had to reload. Memory is fleeting. When you boot the computer, the pages that were assigned before are not necessarily assigned to the same programs. Programs don’t get to put there names on the pages.

Whatever bug caused the page fault in the first place might well occur again, but you should be able to isolate it by process of elimination.

I believe you when you say they told you to do it. I just don’t understand why. Unless when you ghost the image you leave off some post-installation applications.

I’ll stop rambling now. Again, this was simplified and not exact.

5

This sounds to me like a driver problem. No user application should be using non-pageable memory. Probably what happened is a driver was just installed or something was recently changed in the system, and this caused that driver or a different driver to go haywire. Since it’s a problem with the configuration of the drivers on the system, and the configuration is stored on the harddrive, it doesn’t go away when you reboot (as soon as the offending driver is loaded by the system after reboot, it will crash again).

The way to fix this (or at least try to fix this) is to start your computer in Safe Mode (keep hitting F8 while the computer is starting up to get the menu). You can then uninstall anything you recently installed (any peripheral, application, etc.). You can also create system restore points in Windows XP (I think) that let you put your computer in a known good state that you previously saved. All of this only helps, though, if you know what you’re doing :(.

If you don’t know what you’re doing, just be sure that you always have good backups so that you can use that recover disk without fear of losing anything.