Windows Update error 0x80240439: Windows Update agent can't finish starting
Updated
Cleared for publishing after the automated checks on .
What the code means
Microsoft's page says the Windows Update agent starts but can't complete its startup sequence (for example a corrupted data store or damaged registry configuration).
Code facts for 0x80240439
| Code as Windows shows it | 0x80240439 |
|---|---|
| Type | HRESULT (Windows result code) |
| Hexadecimal, 8 digits | 0x80240439 |
| Decimal (unsigned) | 2149844025 |
| Decimal (signed 32-bit) | -2145123271 |
| Severity | failure |
| Facility | 36 FACILITY_WINDOWSUPDATE |
| Group | Windows Update errors |
Read with care
- The last four hex digits (0x0439 = 1081) are not a Win32 error here: the facility is 36, not 7 (FACILITY_WIN32). Reading them as ERROR_CANNOT_DETECT_PROCESS_ABORT would be wrong. ([MS-ERREF]: HRESULT, System Error Codes (1000-1299))
- Microsoft's troubleshooting page for this code calls it WU_E_NOT_INITIALIZED, but Microsoft's WUA Success and Error Codes table gives that name to 0x80240004 (The object could not be initialized.) and does not list 0x80240439. (Troubleshoot Windows Update error 0x80240439, WUA Success and Error Codes)
Where this error shows up
This code shows up while Windows Update or a Windows upgrade is downloading, installing or setting up.
Applies to
Windows client, Windows Server and Azure virtual machines (as listed at the top of the Microsoft page).
These steps come from a Microsoft page written for IT administrators.
4 steps to try, in order
Steps are grouped by the Microsoft page they come from. The page lists only what those pages give; other causes of 0x80240439 are not covered. 3 steps are flagged.
If this page and Microsoft's page differ, follow Microsoft's page.
From: Troubleshoot Windows Update error 0x80240439
Source: Troubleshoot Windows Update error 0x80240439 (Microsoft Learn), checked Nov 14, 2026. © Microsoft, licensed under CC BY 4.0. Steps shortened and reworded by PC Driver Update.
Back up first
Written for IT administrators.
Before you troubleshoot, back up the operating system disk; the Microsoft page asks for this first.
Reset the Windows Update agent
Written for IT administrators.
Changes services or policyRenames system files or foldersIn an administrative Command Prompt run:
net stop wuauserv
net stop bits
net stop cryptSvc
ren %windir%\SoftwareDistribution SoftwareDistribution.old
ren %windir%\System32\catroot2 catroot2.old
net start cryptSvc
net start bits
net start wuauserv
If you run these more than once, delete the existing SoftwareDistribution.old and catroot2.old folders before each later run. Then try the update again.
Microsoft advises: Back up your personal files before you try these fixes. (Back up and restore with Windows Backup)
Microsoft advises: Only try this if you're comfortable working in the command line, and back up your personal files first. (Troubleshoot problems updating Windows)
Reregister Windows Update components
Written for IT administrators.
Changes system filesAt the command prompt run the regsvr32 /s commands the page lists, for example regsvr32 /s atl.dll, regsvr32 /s urlmon.dll, regsvr32 /s wuapi.dll, regsvr32 /s wuaueng1.dll (the page gives 30 DLL names in order, plus 6 more for Windows versions older than Windows 10; open it for the full list).
Restart, and try the update again.
Microsoft advises: Back up your personal files before you try these fixes. (Back up and restore with Windows Backup)
Verify Group Policy settings
Written for IT administrators.
Changes services or policyGenerate a report with: gpresult /h gpresult.html
In the report review Computer Configuration > Administrative Templates > Windows Components > Windows Update for policies that might block initialization, and reconfigure or disable them.
If you make changes run: gpupdate /force
Restart and try again.
Microsoft advises: Back up your personal files before you try these fixes. (Back up and restore with Windows Backup)
The Microsoft page also has a step for Azure virtual machines only and a step for PCs that get updates from WSUS or a similar service; they are not listed here, so follow the Microsoft page for them.
Stop and get help
If these steps do not fix the problem, or you are not sure about a step, stop and get help from Microsoft Support or from the maker of your PC. Stop at once if the data on this computer is at risk: back up your files first, or ask a professional before you go on.
Dates and review
| Automated checks | first check: ; second check: ; third check: ; fourth check: |
|---|---|
| Microsoft pages read |
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| Review status | Cleared for publishing after the automated checks on . |