Fix Windows Update Agent Corrupted (Error 0x80070490)

You're trying to check for updates. It sits on "Checking for updates" for ten minutes. Then it throws error 0x80070490. The message says something vague like "Windows Update ran into a problem." This happens most often after a cumulative update fails mid-install – your PC restarts, rolls back, and from then on, the update agent is busted. I've also seen it after a disk cleanup that nuked the wrong files.

Why This Happens

What's actually happening here is the Windows Update Agent's core DLLs got corrupted or unregistered. The Windows Update service (wuauserv) tries to load these DLLs – wuaueng.dll, wucltux.dll, wups.dll – and fails. So it can't talk to Microsoft's servers. The error code 0x80070490 means the component store is inconsistent. It's not missing entirely; it's just broken.

Skip trying to uninstall recent updates from Control Panel – that won't touch the agent DLLs. And don't run a Windows 10 repair install yet. That's overkill for this problem. The fix is to reset the update components manually.

How to Fix It

You'll need to stop the Windows Update service, delete the corrupted files, and rebuild the component store. Do these steps in order. Don't skip step 2 – it's the real fix.

Open an admin Command Prompt. Press Win + X, select "Windows Terminal (Admin)" or "Command Prompt (Admin)". If you're on Windows 11, Terminal works the same way.
Stop the Windows Update service. Run these commands one at a time:
```
net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
```
This kills the services that hold locks on the corrupted files. If any service won't stop, reboot and try step 2 again before step 3.
Delete the SoftwareDistribution and Catroot2 folders. Run:
```
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 Catroot2.old
```
The reason renaming works is Windows will create fresh folders when the services restart. Don't delete these folders – renaming preserves them if you need to roll back.
Restart the services. Run:
```
net start wuauserv
net start cryptSvc
net start bits
net start msiserver
```
Check they all start without error. If "net start wuauserv" fails, jump to step 5 first.
Rebuild the Windows Update Agent DLLs. This is the critical step. Run:
```
DISM /Online /Cleanup-Image /RestoreHealth
```
DISM scans the component store and replaces corrupted files. Connect to the internet for this. It can take 15 minutes. Don't interrupt it. If DISM fails, you might need to specify a source – see the "Still Fails" section below.
Run SFC to fix system files. After DISM finishes, run:
```
sfc /scannow
```
SFC fixes remaining corruption that DISM didn't catch. I've seen DISM fix the agent DLLs but leave a registry key broken – SFC handles that.
Reboot and test updates. Restart your PC. Go to Settings > Windows Update and click "Check for updates." It should work now.

Still Fails? Check These

If the error persists after step 6, the problem might be deeper. First, check your system date and time – wrong time breaks SSL connections to Microsoft's update servers. Right-click the clock, select "Adjust date/time," and turn on "Set time automatically."

Second, if DISM fails with error 0x800f0906, it means the component store can't find source files. You need a Windows ISO or install media. Mount the ISO (or insert a USB), then run DISM with a source path:

DISM /Online /Cleanup-Image /RestoreHealth /Source:G:\sources\install.wim /LimitAccess

Replace G: with your DVD or USB drive letter. The /LimitAccess flag tells DISM not to use Windows Update as a fallback.

Third, check the CBS log for specific errors. Open an admin Command Prompt and run:

findstr /c:"[SR]" %windir%\logs\cbs\cbs.log > %userprofile%\Desktop\cbs_errors.txt

Open the cbs_errors.txt file on your desktop. If you see lines with "cannot repair member file" and a specific DLL name – like wuaueng.dll – the update agent is beyond manual repair. In that case, a Windows in-place upgrade (keep files and apps) is the cleanest fix. It takes an hour but saves reinstalling everything.

One last thing – if you're on Windows 11 22H2 or later, there's a known bug where the Windows Update cache can't clear after a failed install. After step 4, also run:

del /f /s /q "C:\ProgramData\USOShared\*"

That clears the Update Orchestrator cache. Been the magic step for me on three different machines now.