Windows System Errors

Access Denied

Fatal error during installation

WU_E_PT_HTTP_STATUS_DENIED

Class not registered

Component Store Corrupted — a required Windows Update component is damaged

Update Installation Failed — update service connection or reserved partition issue

I/O Device Error — Windows cannot perform an input/output operation on the specified device

Required Service Missing — Windows cannot find a service needed for the operation

Operation Timed Out — Windows Update waited too long for a response

Assembly Missing — servicing stack could not find a required component package

Element Not Found — Windows could not locate a required servicing component

Driver Compatibility Failure — Windows upgrade rolled back after a driver-related crash

File Not Found

Update Failed

Source Files Not Found

Unspecified Error

The process cannot access the file because it is being used by another process

The service cannot be started, either because it is disabled or has no enabled devices

Invalid Parameter — the system received an argument it cannot process

Fatal System Error — a critical Windows subsystem process terminated, causing the system to halt

Not Enough Disk Space — the target volume has insufficient free space for the operation

Invalid Data — Windows received update data it could not parse

Service Unavailable — the update endpoint returned a temporary server-side failure

Name Resolution Failure — Windows Update could not resolve the required server name

Operation Timeout — a required Windows task did not finish in time

Update Content Incomplete — the downloaded update package could not be used