Windows reports failures as hexadecimal codes and almost never explains them on screen. This index maps every code covered on Sigma Wire to what it actually means, which part of Windows raises it, and the fix that resolves it most often.

Find your code below and go straight to its guide. If your code is not here yet, the Microsoft Update Catalog guide covers the manual-install route that resolves many update failures regardless of the specific code.

Windows Update and servicing errors

These come from Component Based Servicing (CBS) — the part of Windows that installs updates by assembling components out of the component store at C:\Windows\WinSxS.

Code	What it means	Usual cause	Fix that works most often
0x80073712	ERROR_SXS_ASSEMBLY_MISSING — a component manifest is missing from the store	Interrupted servicing stack update	DISM /RestoreHealth
0x800f0805	CBS_E_INVALID_PACKAGE – the package is not applicable	Wrong architecture or Windows version	Match build and architecture, re-download
0x80070002	File not found	Corrupt update cache	Rename SoftwareDistribution
0x800f081f	Source files could not be found	DISM cannot reach a repair source	Local ISO with /Source:WIM
0x800f0922	Failure at the install stage	Full EFI System Partition	Free space on the ESP
0x80070643	Fatal error during installation	.NET Framework or the WinRE partition	Repair .NET, resize WinRE
0x80073d02	Package install blocked	Another deployment still in progress	Finish or clear the pending session
0xc0430001	Servicing operation failed	Servicing stack or component store fault	DISM /RestoreHealth

Download and connectivity errors

These happen before installation — Windows Update could not retrieve what it needed.

Code	What it means	Usual cause	Fix that works most often
0x80244022	Server returned HTTP 503	Proxy, WSUS, or a temporary outage	Bypass the proxy and retry
0x8024200d	Additional content could not be downloaded	Interrupted or partial download	Clear the cache, re-download

COM and service startup errors

These are runtime failures – Windows could not start a background component that an app or service depends on.

Code	What it means	Usual cause	Fix that works most often
0x80080005	CO_E_SERVER_EXEC_FAILURE – server execution failed	The owning Windows service is stopped or disabled	Start the service, or fix DCOM launch permissions

Disk and capacity errors

Code	What it means	Usual cause	Fix that works most often
0x80070070	Not enough disk space	System drive or reserved partition full	Free space, or extend the partition

How to read a Windows error code

Most Windows failure codes are Win32 errors wrapped as an HRESULT. The pattern 0x8007XXXX means “a Win32 error, facility 7”. Strip the 0x8007 and convert what is left from hex to decimal, and you have the underlying Win32 error number.

Worked example: 0x80073712 → 0x3712 → decimal 14610 → ERROR_SXS_ASSEMBLY_MISSING, “The referenced assembly could not be found.”

Codes beginning 0x800F come from CBS itself rather than from Win32, and codes beginning 0x8024 come from the Windows Update Agent — which is why the first two hex groups tell you which subsystem to look at before you know anything else.

Where to find the real reason

The code alone rarely identifies the cause. Two logs carry the detail:

• C:\Windows\Logs\CBS\CBS.log — every servicing operation. Search it for your code and read the lines immediately before the failure.
• C:\Windows\Logs\DISM\dism.log — component store repairs.

Select-String -Path C:\Windows\Logs\CBS\CBS.log -Pattern "0x8007" | Select-Object -Last 40

For a failure tied to one specific update, the KB number is often a faster route than the error code. Look it up in Settings → Windows Update → Update history, then find that KB’s guide on this site.