Windows Error Code Database

ERROR_INVALID_NAME

The Windows product key format is invalid or does not match the installed Windows edition. The activation service rejected the key because it is meant for a different edition (e.g., Enterprise key on Pro).

WU_E_INVALID_PRODUCT_LICENSE

Search may have missed some updates before there is an unlicensed application on the system.

ERROR_GEN_FAILURE

An audio device stopped responding to system requests. The audio controller driver failed to initialize or lost communication with the hardware endpoint.

INACCESSIBLE_BOOT_DEVICE

NTE_BAD_KEYSET

The keyset used for cryptographic operations does not exist. The Windows cryptographic provider cannot find the expected key container, typically after a profile corruption or credential reset.

TRUST_E_CERT_SIGNATURE

The digital certificate signature on a downloaded file could not be verified. The certificate chain validation failed because a root or intermediate certificate is missing, expired, or revoked.

CRITICAL_PROCESS_DIED

A critical system process terminated unexpectedly, and Windows cannot recover. This CRITICAL_PROCESS_DIED blue screen typically results from corrupted system files, a failed driver, or disk errors affecting core OS binaries.

ERROR_FILE_NOT_FOUND

The system attempted to access a file or registry key that does not exist. The expected path is invalid, the file was deleted, or a Windows component references a resource that has been removed.

ERROR_NOT_FOUND

The CBS manifest references a component package that is not present in the Component Store. The Windows servicing stack cannot locate the required package to complete the operation.

ERROR_SXS_ASSEMBLY_MISSING

A side-by-side assembly is missing. The Component Store is corrupted.

CBS_E_SOURCE_MISSING

CBS_E_STORE_CORRUPTION

The Windows Update package is not applicable to this system. The component referenced in the update delta is a different version than what is installed.

WU_E_MISSING_HANDLER

A component required to detect applicable updates was missing.

ERROR_INVALID_DRIVE

The system cannot find the drive specified.

ERROR_WRITE_PROTECT

The media is write protected.

CRC_ERROR

The Cyclic Redundancy Check (CRC) verification failed. Data read from the disk does not match its stored checksum, indicating physical media damage or a failing drive.

ERROR_SECTOR_NOT_FOUND

The drive cannot find the sector requested.

ERROR_SEEK

The drive cannot locate a specific area or track on the disk.

ERROR_NOT_DOS_DISK

The specified disk or diskette cannot be accessed.

ERROR_READ_FAULT

The system cannot read from the specified device.

ERROR_WRONG_DISK

The wrong diskette is in the drive.

ERROR_FAIL_I24

Fail on INT 24.

ERROR_FILE_CORRUPT

A file could not be read because the data on disk is corrupted. The storage media has degraded sectors, or a file system error has rendered the file contents unreadable.

STATUS_NO_SUCH_DEVICE

The boot loader cannot locate the required boot device. The disk containing the Windows partition is not detected by the firmware, or the boot entry points to a device that no longer exists.

BAD_POOL_CALLER

A driver attempted to free memory from the kernel pool that it did not own or that was already freed. This BAD_POOL_CALLER blue screen results from a double-free bug or pool corruption in a kernel-mode driver.

DRIVER_IRQL_NOT_LESS_OR_EQUAL

ERROR_BAD_UNIT

The system cannot find the device specified.

ERROR_GEN_FAILURE

A device attached to the system is not functioning.

ERROR_BAD_REM_ADAP

The remote adapter is not compatible.

ERROR_INSTALL_SERVICE_FAILURE

The Windows Installer service could not be accessed.

FATAL_INSTALLATION_ERROR

The Windows installation process encountered a fatal error. The Recovery Partition may be too small, or the MSI installer engine encountered an unrecoverable condition during package processing.

ERROR_INSTALL_ALREADY_RUNNING

Another installation process is already running. The Windows Installer service only allows one MSI transaction at a time, and a previous installation has not yet released its lock.

PAGE_FAULT_IN_NONPAGED_AREA

A process attempted to access a memory page that should be resident in physical RAM but was not found. This PAGE_FAULT_IN_NONPAGED_AREA blue screen points to a faulty driver, defective RAM, or corrupted system files.

E_OUTOFMEMORY

The warehouse is full. The system has run out of non-paged pool memory.

ERROR_OUT_OF_STRUCTURES

Storage to process this request is not available.

ERROR_NO_PROC_SLOTS

The system cannot start another process at this time.

ACCESS_VIOLATION

A program attempted to read from or write to a memory address that it does not have permission to access. This access violation typically results from a software bug, corrupted DLL, or incompatible driver.

ERROR_SUPPORTED_REQUEST

The Microsoft Store sync protocol version is not supported. The Mail app or another Store app attempted to use a sync method that is incompatible with the current server or client configuration.

ERROR_INSTALL_POLICY_FAILURE

The Microsoft Store app deployment failed because the package could not be registered. The AppX package manager encountered a conflict with an existing installation or a permissions issue on the WindowsApps folder.

ERROR_PACKAGE_REPOSITORY_CORRUPTED

The Microsoft Store package update failed because the required package dependency was not found. A framework package or runtime that the app depends on is missing from the system.

ERROR_DELETING_EXISTING_APPLICATIONDATA

The Microsoft Store could not delete old application data during an update or reinstall. The AppX deployment service failed to clean up previous package data before installing the new version.

E_FAIL

An unspecified error occurred during the operation. In networking contexts, this commonly indicates a file sharing permission issue, SMB protocol version mismatch, or a firewall blocking the connection.

ERROR_BAD_NETPATH

The network path was not found. The target computer or shared folder does not exist on the network, or the SMB service is not running on the remote host.

ERROR_DEV_NOT_EXIST

The specified network resource or device is no longer available.

ERROR_NETNAME_DELETED

The specified network name is no longer available. A mapped network drive or UNC path connection was dropped during the file operation.

ERROR_NETWORK_ACCESS_DENIED

Network access is denied.

ERROR_NETNAME_LIMIT

The network name limit was reached.

ERROR_NET_WRITE_FAULT

A network adapter hardware error occurred.

ERROR_BAD_NET_NAME

The network name cannot be found.

ERROR_TOO_MANY_NAMES

The name limit for the local computer network adapter card was exceeded.

ERROR_TOO_MANY_SESS

The network BIOS session limit was exceeded.

ERROR_ALREADY_ASSIGNED

The local device name is already in use.

ERROR_INVALID_PASSWORD

The specified network password is not correct.

ERROR_NET_WRITE_FAULT

A write fault occurred on the network.

WU_E_NO_CONNECTION

Operation did not complete because the network connection was unavailable.

WU_E_EULA_UNAVAILABLE

License terms could not be downloaded.

ERROR_BAD_NET_RESP

The network responded incorrectly.

ERROR_UNEXP_NET_ERR

An unexpected network error occurred.

ERROR_NETWORK_UNREACHABLE

The network adapter cannot reach the default gateway or any remote host. The local network configuration is incorrect, the adapter is disabled, or there is no active network connection.

WININET_E_CANNOT_CONNECT

WININET_E_CONNECTION_ABORTED

An established network connection was unexpectedly terminated. This typically occurs when antivirus software, a proxy server, or an unstable network drops the active TCP session.

WU_E_INVALID_PROXY_SERVER

The format of the proxy list was invalid.

WU_E_PT_HTTP_STATUS_FORBIDDEN

The Windows Update client received an HTTP 403 Forbidden response from the update server. A proxy server, firewall, or network policy is blocking access to the Windows Update endpoints.

WU_E_PT_WINHTTP_NAME_NOT_RESOLVED

The Windows Update client could not connect to the WSUS or Windows Update server because the server returned an unexpected redirect response.

ERROR_HANDLE_DISK_FULL

The disk is full.

ERROR_DISK_FULL

There is not enough disk space to complete the operation. The system drive does not have sufficient free space for the update download, extraction, or installation.

ERROR_TIMEOUT

A Windows service or operation failed to complete within its allotted timeout period. The service did not respond to the Service Control Manager within the expected timeframe.

MEMORY_MANAGEMENT

The Windows Memory Manager detected a corrupted Page Table Entry (PTE). This indicates physical RAM failure, a driver corrupting memory management structures, or failing hardware.

ERROR_NOT_SAME_DEVICE

You cannot build across the river. The system cannot move files between different partitions during the update.

ACCESS_DENIED

ERROR_NOT_READY

The device is not ready. A removable drive, optical media, or storage device is not accessible because it has been disconnected or is not properly initialized.

CRITICAL_STRUCTURE_CORRUPTION

This security error indicates a compromise or failure in the Windows security subsystem. The critical structure corruption condition was detected by Windows, indicating that the affected component cannot complete its operation.

ERROR_SERVICE_DISABLED

The required Windows service is disabled or stopped and cannot be started. A service dependency is not running, typically because it was disabled in the registry or by Group Policy.

ERROR_SERVICE_DOES_NOT_EXIST

The specified Windows service does not exist in the service database. The Service Control Manager cannot find the service entry, typically because it was deleted or never registered.

ERROR_SERVICE_NOT_ACTIVE

The service has not been started.

RPC_S_CALL_FAILED

The Remote Procedure Call (RPC) failed during inter-process communication. The RPC runtime encountered a communication failure between client and server components, often due to a crashed service or corrupted endpoint.

CO_E_SERVER_EXEC_FAILURE

The DCOM Server Process Launcher service failed to start a COM object. The server execution failed, typically because a required service is disabled or a COM registration is corrupted.

SYSTEM_SERVICE_EXCEPTION

A kernel-mode driver caused an exception while executing a system service routine. The driver attempted an illegal operation such as accessing invalid memory or violating IRQL requirements, triggering a SYSTEM_SERVICE_EXCEPTION blue screen.

SYSTEM_THREAD_EXCEPTION_NOT_HANDLED

A system thread generated an exception that the error handler could not catch. The faulting thread is typically a driver component that encountered an unrecoverable error during execution.

ERROR_INVALID_FUNCTION

Incorrect function called.

ERROR_TOO_MANY_OPEN_FILES

The system cannot open the file because too many files are open.

ERROR_BAD_FORMAT

An attempt was made to load a program with an incorrect format.

ERROR_CURRENT_DIRECTORY

The directory cannot be removed.

ERROR_NO_MORE_FILES

There are no more files.

ERROR_SHARING_VIOLATION

The requested file operation failed because the file is locked by another process. A sharing violation occurs when two or more processes attempt to write to the same file simultaneously.

ERROR_LOCK_VIOLATION

The process cannot access the file because another process has locked a portion of the file.

ERROR_SHARING_BUFFER_EXCEEDED

Too many files opened for sharing.

ERROR_HANDLE_EOF

Reached the end of the file.

ERROR_FILE_EXISTS

The file exists.

ERROR_CANNOT_MAKE

The directory or file cannot be created.

ERROR_INSUFFICIENT_BUFFER

The data area passed to a system call is too small.

ERROR_MOD_NOT_FOUND

A piece of the mosaic is missing. The specific DLL module required cannot be found.

ERROR_PROC_NOT_FOUND

The specified procedure could not be found.

ERROR_CANNOT_COPY

The directory or file cannot be copied.

ERROR_DIRECTORY

A directory operation failed because the target path is invalid or points to a cloud-only placeholder file that cannot be accessed offline. OneDrive files set to "online-only" may trigger this when accessed without a network connection.

ERROR_PRODUCT_VERSION

The timeline is confused. You are trying to install an older version over a newer one.

COR_E_EXCEPTION

A .NET Framework managed exception occurred. The Common Language Runtime (CLR) caught an unhandled exception in a managed application, typically indicating a bug in the application code or a missing dependency.

STATUS_INVALID_IMAGE_FORMAT

The image is flawed. You are trying to run a 32-bit app with 64-bit DLLs (or vice versa).

STATUS_SYSTEM_PROCESS_TERMINATED

A critical Windows subsystem process (csrss.exe or winlogon.exe) terminated unexpectedly. Windows cannot continue operating without these processes and forces a blue screen to prevent further damage.

WININET_E_DECODING_FAILED

The SSL/TLS certificate validation failed during a secure connection. The system clock may be incorrect, a root certificate may be missing, or a proxy is intercepting HTTPS traffic.

E_UNEXPECTED

An unexpected catastrophic failure occurred in the Store database. The AppX package registration is completely out of sync with the installed application state on disk.

ERROR_PATH_NOT_FOUND

The Windows Update agent expected a specific directory structure that does not exist or has been deleted. The SoftwareDistribution folder tree is incomplete or corrupted.

ERROR_INVALID_DATA

The Windows Update manifest contains invalid or malformed data that cannot be parsed. The update catalog metadata has been corrupted, preventing the agent from determining which files to download.

E_INVALIDARG

Windows received invalid parameters during an update operation. The SoftwareDistribution folder contains corrupted download cache files that prevent the update agent from processing the payload correctly.

CBS_E_INSTALLERS_FAILED

The Windows Update installation failed during the safe OS phase. The System Reserved partition is too small, or a VPN connection is interfering with the update process.

WU_E_NO_SERVICE

Windows Update Agent was unable to provide the service.

WU_E_MAX_CAPACITY_REACHED

The maximum capacity of the service was exceeded.

WU_E_UNKNOWN_ID

An ID cannot be found in the update catalog.

WU_E_NOT_INITIALIZED

The object could not be initialized.

WU_E_RANGEOVERLAP

The update handler requested a byte range overlapping a previously requested range.

WU_E_TOOMANYRANGES

The requested number of byte ranges exceeds the maximum.

WU_E_INVALIDINDEX

The index to a collection was invalid.

WU_E_ITEMNOTFOUND

The key for the item queried could not be found.

WU_E_OPERATIONINPROGRESS

The Windows Update agent received a response it could not interpret from the update server. The SOAP envelope from the server contained unexpected or malformed data.

WU_E_COULDNOTCANCEL

Cancellation of the operation was not allowed.

WU_E_NOOP

No operation was required. The system is already up to date.

WU_E_XML_MISSINGDATA

Windows Update Agent could not find required information in the update's XML data.

WU_E_XML_INVALID

The Windows Update service returned duplicate data in its response. The update catalog contains conflicting entries for the same update package.

WU_E_CYCLE_DETECTED

Circular update relationships were detected in the metadata.

WU_E_TOO_DEEP_RELATION

Update relationships too deep to evaluate.

WU_E_INVALID_RELATIONSHIP

An invalid update relationship was detected.

WU_E_REG_VALUE_INVALID

An invalid registry value was read.

WU_E_DUPLICATE_ITEM

Operation tried to add a duplicate item to a list.

WU_E_INVALID_INSTALL_REQUESTED

Updates requested for install are not installable.

WU_E_INSTALL_NOT_ALLOWED

Operation tried to install while another installation was in progress.

WU_E_INSTALL_NOT_ALLOWED

Another Windows Update operation is already in progress. The update agent cannot start a new scan or download while a previous operation has an active lock on the update database.

WU_E_NO_USERTOKEN

Operation failed because a required user token is missing.

WU_E_EXCLUSIVE_INSTALL_CONFLICT

An exclusive update cannot be installed with other updates.

WU_E_POLICY_NOT_SET

A policy value was not set.

WU_E_SELFUPDATE_IN_PROGRESS

The operation could not be performed because the Windows Update Agent is self-updating.

WU_E_INVALID_UPDATE

An update contains invalid metadata.

WU_E_TIME_OUT

Operation did not complete because it timed out.

WU_E_EULAS_DECLINED

The license terms for all updates were declined.

WU_E_NO_UPDATE

There are no updates.

WU_E_USER_ACCESS_DISABLED

Group Policy settings prevented access to Windows Update.

WU_E_INVALID_UPDATE_TYPE

The type of update is invalid.

WU_E_URL_TOO_LONG

The URL exceeded the maximum length.

WU_E_UNINSTALL_NOT_ALLOWED

The update could not be uninstalled because the request did not originate from a WSUS server.

WU_E_LEGACYSERVER

An operation did not complete because it requires a newer version of server.

WU_E_BIN_SOURCE_ABSENT

A delta-compressed update could not be installed because it required the source.

WU_E_SOURCE_ABSENT

A full-file update could not be installed because it required the source.

WU_E_WU_DISABLED

Access to an unmanaged server is not allowed.

WU_E_CALL_CANCELLED_BY_POLICY

Operation did not complete because the DisableWindowsUpdateAccess policy was set.

WU_E_INVALID_FILE

The Windows Update agent policy configuration is invalid. A Group Policy or MDM setting contains conflicting or malformed update policy values.

WU_E_INVALID_CRITERIA

The search criteria string was invalid.

WU_E_DOWNLOAD_FAILED

The Windows Update download failed because the update metadata was corrupted or incomplete. The update agent could not verify the download payload against the expected hash.

WU_E_UPDATE_NOT_PROCESSED

The update was not processed.

WU_E_INVALID_OPERATION

The object's current state did not allow the operation.

WU_E_NOT_SUPPORTED

The functionality for the operation is not supported.

WU_E_WINHTTP_INVALID_FILE

The downloaded file has an unexpected content type.

WU_E_TOO_MANY_RESYNC

Agent is asked by server to resync too many times.

WU_E_NO_SERVER_CORE_SUPPORT

WUA API method does not run on Server Core installation.

WU_E_SYSPREP_IN_PROGRESS

Service is not available while sysprep is running.

WU_E_UNKNOWN_SERVICE

The update service is no longer registered with AU.

WU_E_NO_UI_SUPPORT

There is no support for WUA UI.

WU_E_UNEXPECTED

An unspecified Windows Update error occurred. The update agent encountered a generic failure that does not map to a specific known error condition.

WU_E_UH_NEEDANOTHERDOWNLOAD

Windows Update requires a prerequisite Servicing Stack Update (SSU) before the main update can be applied. The current servicing stack version is too old to process the pending update package.

WU_E_PT_HTTP_STATUS_NOT_FOUND

The Windows Update client received an HTTP 500 Internal Server Error from the update server. The WSUS or Windows Update server encountered an internal processing error.

WU_E_DS_NODATA

The Windows Update metadata XML could not be parsed because it contains a reference to an unsupported or missing schema namespace.

WU_E_AU_NOSERVICE

Automatic Updates was unable to service incoming requests.

DO_E_DOWNLOAD_NO_PROGRESS

Delivery Optimization download made no progress.