My computer has been acting up for the last year, but then works fine for the next month or so. I occasionally get a "blue screen of death" and a data dump and the error message:

IRQL_NOT_LESS_OR_EQUAL

Here's what a Google search shows:

"Explanation:
This Stop message indicates that a kernel-mode process or driver attempted to access a memory address to which it did not have permission to access. The most common cause of this error is an incorrect or corrupted pointer that references an incorrect location in memory. A pointer is a variable used by a program to refer to a block of memory. If the variable has an incorrect value in it, the program tries to access memory that it should not. When this occurs in a user-mode application, it generates an access violation. When it occurs in kernel mode, it generates a STOP 0x0000000A message. If you encounter this error while upgrading to a newer version of Windows, it might be caused by a device driver, a system service, a virus scanner, or a backup tool that is incompatible with the new version.

User Action:
This error usually occurs after the installation of a buggy device driver, system service, or BIOS. To resolve it quickly, restart your computer, and press F8 at the character-mode menu that displays the operating system choices. At the resulting Windows 2000 Advanced Options menu, choose the Last Known Good Configuration option. This option is most effective when only one driver or service is added at a time. If you encounter this error while upgrading from Windows NT 4.0 or earlier, it might be caused by a device driver, a system service, a virus scanner, or a backup tool that is incompatible with the new version. If possible, remove all third-party device drivers and system services and disable any virus scanners prior to upgrading. Contact the software manufacturers to obtain updates of these tools. For additional error messages that might help pinpoint the device or driver that is causing the error, check the System Log in Event Viewer. Disabling memory caching of the BIOS might also resolve this error. You should also run hardware diagnostics supplied by the system manufacturer, especially the memory scanner. For details on these procedures, see the owners manual for your computer. If your system has small computer system interface (SCSI) adapters, contact the adapter manufacturer to obtain updated Windows 2000 drivers. Disable sync negotiation in the SCSI BIOS, check the cables and the SCSI IDs of each device, and confirm proper termination. For enhanced integrated device electronics (EIDE) devices, define the onboard EIDE port as Primary only. Also, check each EIDE device for the proper master/slave/stand-alone setting. Remove all EIDE devices except for hard disks. If the message appears during an installation of Windows 2000, make sure that the computer and all installed peripherals are listed on the Microsoft Windows 2000 Hardware Compatibility List (HCL) on http://www.microsoft.com. For more troubleshooting information about this Stop message, refer to the Microsoft Knowledge Base at http://support.microsoft.com/support."

I've had this several times before (about once a month for the past year!). After the blue screen, Windows loads and everything is normal. Strange.

I have Windows XP, SP3, and my computer is about 2-1/2 years old.

It seems a system process - either the system itself or a device driver - is having problems. The first two candidates for this are usually the driver for the graphics card and the network card. Try updating both with the latest version.

You should also definitely apply SP4 for your XP - a SP3 XP is quite vulnerable and may not run some software.

If neither fix helps, the error may be on the hardware side - the very low frequency might suggest a small problem in the hardware. In that case, it might be best to just live with it and save your work more frequently.

Hope this helps,

Wes

I thought SP3 was the latest available for XP. Is this web page wrong?

http://windows.microsoft.com/en-us/windows/products/lifecycle

How, exactly, do I identify what my graphics card and network card are? "Device Manager" (via "Administrative Tools" on "Control Panel" lists several choices.

It could be overheating (make sure the fans, processor cooling fins and ventilation slots aren't clogged with dust). It could be a hardware fault. Make sure all the plugs and boards are properly seated. Also, I'm sure in researching the problem, you also read about possible Registry corruption. Perhaps also suspect this and do a repair installation of the operating system (clean installation preferable). Then you can you eliminate the problem being software related. After that, look to your hardware as being a possible cause.

I'm not aware of the existence of SP4 for Windows XP.

You're right, it was not called SP4. Microsoft released a cumulative upgrade when XP was moved from full support to the current extended support to enable customers to quickly get to that level of upgrades, but it was never formally termed a Service Pack. It was a one-shot compilation of the standard online updates until that point.

You'll have that stuff already if you have Windows Upgrade enabled.

(That's what I get for installing way too many XP boxes. I'm so used to applying this one pack after install that I automatically called it SP4 and even have it labeled as such on the CD...)

Wes

Under normal circumstances, drivers will be updated through Windows Update. However, you can identify and update your graphics card driver via one of the sites listed here:

http://sketchup.google.com/support/bin/answer.py?hl=en&answer=36254

If it's an Intel driver, they have an online driver identification utility that will tell you if you need an update. (The other sites may do that too, but my computer is Intel so I know that works.)

Your network card will be listed in Device Manager under Network Controllers - rightclick on it and click to search for a driver update online.

I've had trouble with graphics drivers supplied via Windows Update. The graphics card on my current computer is a Radeon HS 3800. I accepted an update for it from Microsoft and all seemed OK at first. A while later, I noticed that some games wouldn't run properly in full-screen mode ('Bookworm' was one). I rolled back the driver to the previous one and all was well. I then went to the Radeon site and downloaded the latest driver from there. This one gave no problems at all.

I had a difficulty some years ago with a graphics driver from Windows Update but thought I'd give it another try. However, it seems a graphics card driver from there can still can give problems. This may not be the case for everyone but perhaps consider turning down the offer of a graphics card driver from Windows Update and get it from the graphics card manufacturers site instead.

In most circumstances, the only graphics card drivers you should trust are those directly from the manufacturer of the card. Most graphics cards come with some sort of control center where you can make settings beyond those supported by the standard Windows Display Properties widget. If you can't find it in the start menu or in the system tray at the bottom right, try calling up the display properties (right-click an empty desktop area and choose "properties") and check if you have an extra tab behind "Advanced". It will likely bear the manufacturer name or logo. Select that tab and then look for something like "Launch control center". A new application will start and most likely, somewhere in there will be a function to check for the latest driver and if necessary, upgrade to it. How exactly, I can unfortunately not tell you - every manufacturer uses their own user interface design.

Wes