Windows Update Error 0xC1900107 — Upgrade Cleanup Required Fix

What Does This Error Mean?

Windows Update error 0xC1900107 means a cleanup operation from a previous Windows feature upgrade has not completed. When Windows upgrades to a new major version (like upgrading from Windows 10 to Windows 11), it keeps the old Windows files for a limited time so you can roll back. When a new upgrade attempt begins before this cleanup is fully done, it blocks and shows 0xC1900107. Completing the previous upgrade cleanup — or forcing a disk cleanup — lets the new upgrade proceed.

Affected Models

Windows 10
Windows 11

Common Causes

Previous Windows files (Windows.old folder) have not been cleaned up after an earlier feature update
A previous upgrade was interrupted and left cleanup tasks incomplete
Disk space is too low for the upgrade to proceed — the cleanup data plus the new upgrade cannot both fit
Windows Update history shows a previous upgrade as pending cleanup but the task never ran
The system has multiple pending cleanup tasks that are blocking a new upgrade attempt

How to Fix It

Run Disk Cleanup and clean up Windows Update files. Search 'Disk Cleanup' in Start and open it. When it finishes scanning, click 'Clean up system files' at the bottom. On the second screen, check 'Previous Windows installation(s)', 'Windows upgrade log files', and 'Temporary Windows installation files'. Click OK.

This deletes the Windows.old folder and other upgrade remnants that are blocking the new upgrade. It can free 10-30 GB of space.
Ensure you have at least 20 GB free on the C: drive after running Disk Cleanup. Feature upgrades need significant working space. If you are still short, move large personal files to an external drive temporarily.

The upgrade process needs room for both the new Windows files and temporary working space during installation. Less than 20 GB free on C: causes upgrade failures.
Restart your PC after running Disk Cleanup, then try the Windows Update again. A fresh boot ensures all cleanup tasks have properly completed before the new upgrade begins.

Some cleanup tasks only fully finalize after a restart. Skipping the restart can leave the system in the same blocked state.
If the error persists, try the Windows Update Troubleshooter. Go to Settings > System > Troubleshoot > Other troubleshooters and run the Windows Update troubleshooter. It checks for pending cleanup flags in the Windows Update registry.

There are registry flags that track upgrade cleanup status. The troubleshooter can reset these flags if they are stuck.
As an alternative, download the Windows installation media directly from Microsoft and run it to upgrade. Go to microsoft.com/software-download, download the Installation Assistant or Media Creation Tool for your Windows version, and run it. This method bypasses Windows Update entirely and handles cleanup on its own.

The Installation Assistant is often more reliable than Windows Update for feature upgrades. It performs its own pre-upgrade checks and cleanup.

When to Call a Professional

This error is reliably fixable through Disk Cleanup alone in most cases. If Windows.old cannot be deleted and disk space remains critically low, a technician can safely remove it manually and verify the system is healthy before retrying the upgrade.

Frequently Asked Questions

What is the Windows.old folder?

When Windows performs a major upgrade (like going from version 21H2 to 22H2, or from Windows 10 to Windows 11), it saves a copy of the old Windows installation in a folder called Windows.old. This lets you roll back to the previous version within 10 days if something goes wrong. After 10 days, Windows is supposed to delete Windows.old automatically. Sometimes this automatic deletion does not happen, and the folder accumulates — blocking future upgrades because the disk looks full or because the cleanup task is still marked as pending.

Is it safe to delete Windows.old?

Yes, if your current Windows installation is working well. Windows.old only lets you roll back to the previous Windows version. Once you are happy with the current version and more than 10 days have passed, there is no reason to keep it. Deleting it through Disk Cleanup (not manually through File Explorer) is the safest method. Disk Cleanup ensures all related files are removed correctly.

How much space does Windows.old take up?

Typically between 10 GB and 30 GB, depending on how long Windows has been installed and how many programs are installed. On systems that have done multiple upgrades without cleaning up, the combined upgrade debris can reach 40 GB or more. Running Disk Cleanup > Clean up system files and selecting all upgrade-related options will reclaim all of this space.