How to fix
Windows update error 0xc1900403
on Windows

Hey, so I have this problem where I can't install the latest Windows update for some reason. I tried for a few days, thinking that maybe it would finally go through, but to no avail. Every single time, the error code provided is 0xc1900403.

Windows updates keep Windows up to date and secure by bringing vital security patches, bug fixes, and new features with constant releases. But the Windows update error 0xc1900403 can halt this process in between, normally displaying an error like Something went wrong, halting the updating. This error can lead to repeated update prompts or sluggish system performance, hence leaving your device vulnerable to unpatched attacks.

The 0xc1900403 error is typically the result of issues with the update process or system setup. A common cause is a corrupt update cache in the SoftwareDistribution folder, which holds temporary update files - clearing out the contents of this folder might fix the issue by triggering a new download.

System files can become corrupted to block the update process from taking place, although SFC and DISM scans can fix them and restore functionality. Additionally, conflicts from third-party software, e.g., from antivirus software, might be causing disturbance in updates, and performing a Clean Boot can help in identifying and removing such conflicts.

The steps below provide several solutions, starting with simple steps like running the troubleshooter and moving towards more complex methods like a clean update, to fix Windows update error 0xc1900403. For a quicker fix, we suggest that you use [d1], a PC repair software that can automatically repair system problems that may be causing this error.

Fix 1. Run the Windows Update troubleshooter

The built-in troubleshooter can detect and fix issues preventing updates from installing.

• Type Troubleshoot in Windows search and hit Enter.
• Select Additional troubleshooters/Other troubleshooters.
• Find Windows Update from the list and select Run the troubleshooter/Run.
• Wait till the scan is finished - you will be provided with potential causes so you can proceed with fixes.
• If no suggestions were provided, proceed with the solutions below.

Fix 2. Use the "Fix problems using Windows Update" feature

There's another built-in feature that can sometimes resove Windows update issues automatically.

• Right-click on Start and pick Settings.
• Go to the System section and select Recovery.
• There, you should see the Fix problems using Windows Update option.
• Click Reinstall now.
• Follow the on-screen instructions to finish the process.
• Wait till the computer restarts and try installing the Windows update again.

Fix 3. Restart your computer

A simple restart can resolve temporary glitches affecting the update process.

• Safely eject the external hard drive from your computer.
• Click on the Start menu.
• Select Restart.
• Wait for your computer to restart.

Fix 4. Free up disk space

Insufficient disk space can prevent updates from installing properly.

• Type Disk Cleanup in Windows search and hit Enter.
• If your Windows is installed on drive C, pick it from the list (it should be by default) and press OK.
• Click Clean up system files.
• Select your main disk again and click OK.
• Here, select the largest portions of the data used - these typically include Temporary Internet Files, Windows Update, Temporary Files, Recycle Bin, Delivery Optimization Files, and others.
• Click OK - the process should be finished shortly.

Fix 5. Repair corrupted files

Corrupted system files can block updates, and repairing them can help.

• Type cmd in Windows search.
• Right-click on Command Prompt and select Run as administrator.
• The User Account Control (UAC) window will ask whether you want to allow changes to your computer - click Yes.
• Paste the following command into the new window:
  sfc /scannow
• Press Enter and wait till the scan is executed.
• Once done, run this set of commands, pressing Enter after each:
  DISM /Online /Cleanup-Image /CheckHealth
  DISM /Online /Cleanup-Image /ScanHealth
  DISM /Online /Cleanup-Image /RestoreHealth
  (Note: if you get an error executing this last command, add /Source:C:\RepairSource\Windows /LimitAccess to it and try again).
  
• Restart your computer.

Fix 6. Reset Windows Update components

A corrupted update cache in the SoftwareDistribution folder can halt the update process.

• Open Command Prompt as administrator.
• Stop the Windows Update-related services by running the following commands one at a time, pressing Enter after each one:
  net stop wuauserv
  net stop cryptSvc
  net stop bits
  net stop msiserver
• Rename the SoftwareDistribution and Catroot2 folders by running the following commands:
  ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
  ren C:\Windows\System32\catroot2 Catroot2.old
  Note: If your Windows installation is not on the C drive, replace "C" with the appropriate drive letter.
• Restart the Windows Update-related services by running the following commands:
  net start wuauserv
  net start cryptSvc
  net start bits
  net start msiserver
• Restart your computer.

Fix 7. Manually install the update

If the automatic update fails, downloading and installing it manually can bypass the issue.

• Type in Updates in Windows search and press Enter.
• Select View update history.
• Find the update that failed with the 0xc1900403 error and copy its KB number.
• Open your browser and go to Microsoft Update Catalog.
• Within the search bar, type in the KB number and click Search.
• Find the correct version of the update for your operating system (to check this, right-click on Start and pick System. Under Device specifications and check the System type) and click Download.
• Use on-screen guidelines to finish the installation process and restart your computer.