Windows Update error 0x80240034: how to fix “Update failed to download”

Applies to: “Download error – 0x80240034” and “Install error – 0x80240034” in Windows Update on Windows 11 and Windows 10, for monthly updates and feature updates.

What error 0x80240034 means

Microsoft’s Windows Update error reference lists 0x80240034 as WU_E_DOWNLOAD_FAILED, with the description “Update failed to download.” It’s a general download failure, not a sign that the update itself is broken. The usual causes are:

• An unstable connection, or a VPN, proxy or firewall that blocks or interrupts Microsoft’s download servers.
• Partly downloaded or damaged files in the Windows Update cache (C:\Windows\SoftwareDistribution).
• Not enough free space on the system drive for the download.
• Damaged system files that Windows Update depends on.
• On work PCs, a WSUS server or network filter that doesn’t serve the file.

Don’t confuse it with 0x80244034, a different code about a CAB file that couldn’t be decompressed.

Quick checks first

• Restart the PC and run Settings > Windows Update > Check for updates again. Windows 10: Settings > Update & Security > Windows Update.
• Disconnect any VPN and turn off proxy settings under Settings > Network & internet > Proxy unless your workplace requires them.
• Make sure the connection isn’t metered: open Settings > Network & internet, select your Wi-Fi or Ethernet connection and check that Metered connection is off. Also check Settings > Windows Update > Advanced options for Download updates over metered connections.
• Free up space on the C: drive. Feature updates need much more room than monthly updates.
• Temporarily turn off third-party antivirus or firewall software, then try again. Turn it back on afterwards.
• Check the date, time and time zone are correct under Settings > Time & language > Date & time.

Fix 1: Run the Windows Update troubleshooter

Microsoft’s own guidance is to start with the Windows Update troubleshooter, which checks the update services and resets components that need it.

• Windows 11: open Settings > System > Troubleshoot > Other troubleshooters and select Run next to Windows Update. On recent builds this may open the Get Help app, which runs the same checks.
• Windows 10: open Settings > Update & Security > Troubleshoot > Additional troubleshooters, select Windows Update and choose Run the troubleshooter.

Apply any fixes it suggests, restart and check for updates again.

Fix 2: Reset the Windows Update download cache

If the troubleshooter doesn’t help, clear the download cache so Windows fetches fresh copies. Right-click Start, open Terminal (Admin) (Windows PowerShell (Admin) on Windows 10), type cmd and press Enter, then run these commands one at a time:

net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 Catroot2.old
net start wuauserv
net start cryptSvc
net start bits
net start msiserver

These are the same reset commands a Microsoft moderator recommended for this error. Renaming the folders doesn’t delete anything you need: Windows creates new ones and re-downloads what it needs. Restart the PC and check for updates. If a ren command says access is denied, a service is still running; run its net stop command again. For a full explanation of these commands, see how to run Windows Update from the command line.

After a few successful updates, you can delete the SoftwareDistribution.old and Catroot2.old folders to reclaim space.

Fix 3: Repair system files with DISM and SFC

If the cache reset doesn’t help, repair the Windows component store and system files. In the same administrator window, run:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

DISM can take a while and may appear stuck at a percentage; let it finish. Restart afterwards. If DISM fails with its own error, see error 0x800f081f.

Fix 4: Install the update manually

1. In Settings > Windows Update, note the KB number of the failed update (for example KB5xxxxxx). It’s also listed under Update history.
2. Open the Microsoft Update Catalog and search for that KB number.
3. Download the version that matches your Windows version and system type (x64 or Arm64). You can check both under Settings > System > About.
4. Double-click the downloaded .msu file to install it, then restart.

This bypasses the Windows Update download step completely, so it often works when 0x80240034 keeps repeating for one specific update.

Fix 5: For feature updates, use Microsoft’s upgrade tools

If the error appears when installing a new Windows version (a feature update), download it a different way. On Windows 11, use the Installation Assistant from Microsoft’s Windows 11 download page, or create installation media and run setup.exe from it to upgrade in place while keeping your files and apps. Back up important files first. If setup itself fails with a different code, see error 0xC1900101 – 0x20017.

On a work PC managed by WSUS

If many PCs on a company network fail with 0x80240034, the problem is usually on the update server or network, not the PCs. Ask IT to check that the WSUS server has downloaded and approved the files, and that a proxy, firewall or web filter on the server isn’t blocking them. In one case reported on Microsoft Q&A, a URL filtering tool on the WSUS server was blocking .exe downloads, which broke feature updates and Defender definition updates on every client.

Related guides

• How to run Windows Update from the command line
• “We couldn’t connect to the update service”: how to fix it
• Error 0x800f081f: how to fix it
• Error 0x80070426: how to fix it
• Error 0xC1900101 – 0x20017: how to fix it

Official sources: for more detail, see these pages:

• Microsoft Learn: Windows Update error codes
• Microsoft Learn: Windows Update additional resources (reset components)
• Microsoft Update Catalog

Frequently asked questions

Is error 0x80240034 dangerous?

No. It only means a download failed. Your PC keeps working, but it won’t get that update until the download succeeds, so it’s worth fixing.

Will resetting Windows Update delete my files?

No. The reset only renames Windows Update’s own cache folders. Your files, apps and settings aren’t touched, though your Update history list may look shorter afterwards.

Why does only one update fail with 0x80240034?

That update’s cached download is often damaged. Resetting the cache (Fix 2) or installing it from the Microsoft Update Catalog (Fix 4) usually solves it.

Can a VPN cause 0x80240034?

Yes. VPNs and proxies can interrupt or block downloads from Microsoft’s servers. Disconnect it while updating, then reconnect.