Alphabetical list of BSoD errors

There are a whole bunch of possible BSoD messages; probably more than a hundred. However, only about 20 happen frequently enough that they might imply that an actual problem exists. More than likely, you’ve seen at least one of the following stop messages on your own system:

Attempted Write To Readonly Memory (stop code 0X000000BE)
A faulty driver or service is typically responsible for this error, as is outdated firmware. If the name of a file or service is specified, try uninstalling the software (or rolling back the driver if it’s an upgrade). Check with the manufacturer for firmware and driver updates.

Bad Pool Caller (stop code 0X000000C2)
Causes and remedies are similar to “Attempted Write To Readonly Memory.” Additionally, this error might also be the result of a defective hardware device.

If you encounter this message while upgrading to Windows 7 (see Chapter 1), it may mean that one or more devices in your system are not compatible with the new OS. Try disconnecting unnecessary devices, or at least look for updated drivers and firmware. Also, disable any antivirus software you may have running.

Data Bus Error (stop code 0X0000002E)
This can be caused by defective memory (see Test for Bad Memory (RAM)), including system RAM, the Level 2 cache, or even the memory on your video card. Other causes of this error include serious hard disk corruption, buggy hardware drivers, or physical damage to the motherboard. See What to Do When Windows Won’t Start for one way to test your PC’s memory.

Driver IRQL Not Less Or Equal (stop code 0X000000D1)
Drivers programmed to access improper hardware addresses typically cause this error. Causes and remedies are similar to “Attempted Write To Readonly Memory (stop code 0X000000BE),” earlier in this list.

Driver Power State Failure (stop code 0X0000009F)
This error is caused by an incompatibility between your computer’s power management and one or more installed drivers or services, typically when the computer enters the Hibernate state (discussed at length in Chapter 5). If the name of a file or service is specified, try uninstalling the software (or rolling back the driver if it’s an upgrade). Or, try disabling Windows’ support for Hibernation altogether. See Appendix A for BIOS settings that may affect your PC’s support for power management features.

Driver Unloaded Without Cancelling Pending Operations (stop code 0X000000CE)
Causes and remedies are similar to “Attempted Write To Readonly Memory (stop code 0X000000BE),” earlier in this section.

Driver Used Excessive PTEs (stop code 0X000000D8)
Causes and remedies are similar to “No More System PTEs (stop code 0X0000003F),” later in this section.

Hardware Interrupt Storm (stop code 0X000000F2)
This error occurs when a hardware device (such as a USB or SCSI controller) fails to release an IRQ, a condition typically caused by a buggy driver or firmware. This error can also appear if two devices are incorrectly assigned the same IRQ (discussed later in this chapter). Sometimes just moving an expansion card (desktop PCs only) from one slot to another can fix this problem.

Inaccessible Boot Device (stop code 0X0000007B)
You may see this error during Windows startup if Windows cannot read data from the system or boot partitions (described in Chapter 1). Faulty disk controller drivers are often to blame, but this problem can also be caused by hard disk errors.

If you have a multiboot system, a corrupt Boot Manager configuration may cause this problem; see Modify the Boot Manager configuration for details. If all is well with your drivers and your drive, and you haven’t been messing with the Boot Manager, check your system BIOS settings (described in Appendix A).

If you encounter this message while upgrading to Windows 7 (see Chapter 1), it may mean that one or more devices in your system are not compatible with the new OS. Try disconnecting unnecessary devices, or at least look for updated drivers and firmware. Also, disable or update any antivirus software you may have running.

Kernel Data Inpage Error (stop code 0X0000007A)
This error implies a problem with virtual memory (discussed in Chapter 5), most often in the case that Windows wasn’t able to read data from—or write data to—the swap file. Possible causes include bad sectors, a virus, bad memory, or physical damage to the motherboard or disk controller.

Kernel Stack Inpage Error (stop code 0X00000077)
Causes and remedies are similar to the previous entry, “Kernel Data Inpage Error (stop code 0X0000007A).”

Kmode Exception Not Handled (stop code 0X0000001E)
A faulty driver or service is sometimes responsible for this error, as are memory and IRQ conflicts, and faulty firmware. If the name of a file or service is specified, try uninstalling the software (or rolling back the driver if it’s an upgrade).

If the Win32k.sys file is mentioned in the message, the cause may be third-party remote control software (discussed in Chapter 7).

This error can also be caused if you run out of disk space while installing an application or if you run out of memory while using a buggy application with a memory leak.

No More System PTEs (stop code 0X0000003F)
Page Table Entries (PTEs) are used to map RAM as it is divided into page frames by the Virtual Memory Manager (VMM). This error usually means that Windows has run out of PTEs.

Aside from the usual assortment of faulty drivers and services that can cause all sorts of problems, this error can also occur if you’re using multiple monitors.

NTFS File System (stop code 0X00000024)
This is caused by a problem with Ntfs.sys, the driver responsible for reading and writing NTFS volumes (see Chapter 5). If you’re using the FAT32 filesystem, you may see a similar message (with stop code 0X00000023).

Causes include a faulty IDE or SCSI controller, improper SCSI termination, an overly aggressive virus scanner, or errors on the disk; try testing your drive with Chkdsk, as described earlier in this chapter.

To investigate further, open the Event Viewer (eventvwr.msc), and look for error messages related to SCSI or FASTFAT (in the System category), or Autochk (in the Application category).

Page Fault In Nonpaged Area (stop code 0X00000050)
Causes and remedies are similar to “Attempted Write To Readonly Memory (stop code 0X000000BE),” earlier in this list.

Status Image Checksum Mismatch (stop code 0Xc0000221)
Possible causes for this error include a damaged swap file (see the discussion of virtual memory in Optimize Virtual Memory and Cache Settings), or a corrupted driver. See “Attempted Write To Readonly Memory (stop code 0X000000BE),” earlier in this section, for additional causes and remedies.

Status System Process Terminated (stop code 0Xc000021A)
This error indicates a problem with either Winlogon.exe or the Client Server Runtime Subsystem (CSRSS). It can also be caused if a user with administrator privileges has modified the permissions (see Chapter 8) of certain system files such that Windows cannot read them. To fix the problem, you’ll have to install a second copy of Windows 7 (see Set Up a Dual-Boot System), and then repair the file permissions from there.

Thread Stuck In Device Driver (stop code 0X000000EA)
Also known as the infamous “infinite loop” problem, this nasty bug has about a hundred different causes. What’s actually happening is that your video driver has essentially entered an infinite loop because your video adapter has locked up. Microsoft has posted a solution on its website that involves disabling certain aspects of video acceleration, but I’ve never encountered an instance where this worked. Instead, try the following:

If you’re using a desktop PC, try upgrading your computer’s power supply. A power supply of poor quality or insufficient wattage will be unable to provide adequate power to all your computer’s components, and may result in a “brown out” of sorts in your system. Note that newer, more power-hungry video adapters are more susceptible to this problem. See Don’t Overlook the Power Supply.

Make sure you have the latest driver for your video card. If you older driver to see whether that solves the problem.

Make sure you have the latest driver for your sound card, if applicable. Also, make sure your sound card is not in a slot immediately adjacent to your video card (desktop PCs only), lest the resulting interference or heat disrupt the operation of either card.

Inspect your video card and motherboard for physical damage.

For desktop PCs only: make sure your video card is properly seated in its PCI-E, AGP, or PCI slot. If applicable, try moving it to a different slot. Next, try messing with some of your system’s BIOS settings, especially those concerning your video card slot or video subsystem, as described in Appendix A. For example, if your AGP slot is set to 8x mode, and your video adapter only supports 1x AGP mode, then you’ll want to change the setting accordingly.

Make sure your computer and your video card are adequately cooled. Overheating can cause your video card’s chipset to lock up.

Check with the manufacturer of your motherboard for newer drivers for your motherboard chipset.

For example, the “infinite loop” problem is common among motherboards with VIA chipsets and nVidia-based video cards. Visit the VIA website (http://www.viaarena.com/?pageid=64) for updated drivers and additional solutions.

Try replacing your system’s driver for the Processor-to-AGP Controller. Open Device Manager (devmgmt.msc), expand the System devices branch, and double-click the entry corresponding to your Processor-to-AGP Controller. Choose the Driver tab, and click Update Driver to choose a new driver. Unless you can get a newer driver from the manufacturer of your motherboard chipset, try installing the generic “PCI standard PCI-to-PCI bridge” driver shown in the Hardware Update Wizard.

If your motherboard has an on-board Ethernet adapter, try disabling the PXE Resume/Remote Wake Up option in your system BIOS (see Appendix A).

Unexpected Kernel Mode Trap (stop code 0X0000007F)
Typical causes of this error include defective memory, physical damage to the motherboard, and excessive processor heat due to overclocking (running the CPU faster than its specified clock speed).

Unmountable Boot Volume (stop code 0X000000ED)
This means that Windows was unable to mount the boot volume, which, if you have more than one drive, is the drive containing Windows (see Chapter 1 for more information on the boot and system volumes). This can be caused by using the wrong cable with a high-throughput IDE controller (more than 33 MB/second); try an 80-pin cable instead of the standard 40-pin cable. See also “Inaccessible Boot Device (stop code 0X0000007B),” earlier in this list.

Stop code 0x0000008E
This error, which typically has no title, is often caused by bad memory. But it could also be the result of a rootkit infestation, described in Viruses, Malware, and Spyware.

If you get repeated BSoD errors, and the previous remedies don’t work, try installing a second copy of Windows on your PC, as described in Set Up a Dual-Boot System. If the second copy of Windows exhibits the same problem, then the cause is your hardware. But if the second copy runs well, then your best bet is to copy your data over to the new installation, and abandon the old OS.


[6] The term worm is said to have its roots in the writings of J.R.R. Tolkien, who described dragons in Middle Earth that were powerful enough to lay waste to entire regions. Two such dragons (Scatha and Glaurung) were known as “the Great Worms.” The Great Worm, a virus written by Robert T. Morris in 1988, was particularly devastating, mostly because of a bug in its own code. (Source: Jargon File 4.2.0.)