How to fix the 0xC1900101 driver rollback error during a Windows upgrade
This is a Windows upgrade error that rolls the install back to your old version, almost always because a driver or device is incompatible with the new build. The second code after it points at the phase that failed. Jump to your situation below or work through the methods in order.
By Neeraj Singh ~10 min Updated Jun 2026 88% found this helpful
Error message
0xC1900101 - 0x20017 / 0x30018 / 0x4000D. The installation failed in a phase and rolled back to the previous version of Windows.
Summary
0xC1900101 is a family of Windows upgrade rollback errors, always paired with a second extension code such as 0x20017 or 0x4000D. It almost always means a driver or device is incompatible with the new Windows build: setup gets part way, hits the problem, and rolls back to your previous version so you are not left with a broken system. The usual culprits are outdated storage, graphics, network or USB drivers, third-party antivirus, connected external devices, or too little free disk space. The extension code tells you which phase failed, which narrows down the area. The fix is to update or remove the conflicting driver, disconnect non-essential devices, temporarily remove third-party security software, free disk space, repair the system files, and retry, falling back to a clean boot or the Installation Assistant if needed.
What this error means
A Windows feature update is a full operating-system swap that runs in phases: it copies the new build, migrates drivers and settings, then boots into the new version. If something fails in one of those phases, setup does not leave you stranded, it rolls the whole thing back to the working version and reports 0xC1900101 with an extension code.
That extension code is the clue. A SAFE_OS or boot-phase code usually points at a storage or boot driver, while a migration-phase code points at a device or app driver. So this is not really an update bug, it is the new build refusing an incompatible driver, and the fix is to clear that driver or device out of the way before trying again.
Common causes
An outdated or incompatible driver (storage, graphics, network or USB).
Third-party antivirus interfering with the upgrade.
Connected external or USB devices the new build chokes on.
Too little free disk space for the upgrade.
Corrupt Windows Update components or component store.
A pending or locked driver from a previous install.
An outdated BIOS or firmware.
Expert insight
“0xC1900101 is the upgrade saying a driver said no, so it backed out to keep you safe. I always read the second code first, the SAFE_OS and boot-phase ones point me at storage and boot drivers, the migration ones at a device or app. Then it is the boring but reliable routine: update the obvious drivers, unplug every gadget that is not the keyboard and mouse, pull third-party antivirus for an hour, and make sure there is room on the disk. Nine upgrades out of ten go through clean after that.”
Manager, Tech Support & Operations · 19+ years fixing Windows and system errors
✓ How to fix it
Method 1
Read the extension code
1Note the code after 0xC1900101, for example 0x20017 (SAFE_OS boot), 0x30018 (driver migration) or 0x4000D (migration).
2Boot-phase codes point at storage and boot drivers; migration codes point at a device or app driver.
3This narrows where to look.
Method 2
Update or remove the conflicting driver
1Update storage (SATA/NVMe/RAID), graphics, network and chipset drivers from the device or PC maker, not just Windows Update.
2Uninstall a driver or device you suspect, then retry the upgrade and re-add it after.
3Outdated storage and GPU drivers are the most common offenders.
Method 3
Disconnect external devices
1Unplug all non-essential USB and external devices, leaving only the keyboard and mouse.
2Dongles, external drives, printers and capture devices commonly break the migration phase.
3Retry the upgrade with them disconnected.
Method 4
Remove third-party antivirus
1Temporarily uninstall third-party antivirus and security tools, which often block the upgrade.
2Windows Defender alone is fine during the upgrade.
3Reinstall your security software afterwards.
Method 5
Free disk space
1A feature update needs several GB free. Use Disk Cleanup or Storage Sense to clear space.
2Remove the old Windows.old and temporary files if present.
3Then retry.
Method 6
Repair update components and system files
1Reset Windows Update components and clear the SoftwareDistribution cache.
2Run DISM /Online /Cleanup-Image /RestoreHealth then SFC /scannow.
3This clears a corrupt component store that can also cause 0xC1900101.
Method 7
Clean boot or use the Installation Assistant
1Perform a clean boot (disable startup apps and non-Microsoft services) and retry.
2Or run the Windows Installation Assistant, or upgrade from a mounted ISO, which can get past a stuck update path.
3Re-enable startup items afterwards.
The extension code is your map: boot-phase codes mean storage and boot drivers, migration codes mean a device or app driver. Update the obvious drivers, unplug everything non-essential, and pull third-party antivirus before you retry. A clean boot or upgrading from an ISO is the reliable fallback when the in-place update keeps rolling back.
Frequently asked questions
What does error 0xC1900101 mean?
It is a Windows upgrade rollback error, almost always caused by an incompatible driver or device. Setup fails in a phase and rolls back to your previous version, reporting 0xC1900101 with an extension code.
What does the second code after 0xC1900101 mean?
It identifies the phase that failed. Boot-phase codes such as 0x20017 point at storage and boot drivers, while migration codes such as 0x4000D point at a device or application driver.
How do I find the driver causing it?
Update storage, graphics, network and chipset drivers, unplug external devices, and remove third-party antivirus. The extension code points at the area, so start with storage and boot drivers for boot-phase codes.
Do I need to remove my antivirus?
Temporarily, yes. Third-party antivirus commonly blocks the upgrade. Uninstall it for the upgrade, rely on Windows Defender during it, then reinstall afterwards.
How much disk space does the upgrade need?
Several GB free on the system drive. Use Disk Cleanup or Storage Sense, and remove Windows.old and temporary files, then retry.
What if it keeps rolling back?
Do a clean boot to remove software conflicts, or upgrade from a mounted ISO or the Installation Assistant, which can get past a stuck update path.
Still not working?
If the upgrade still rolls back after updating drivers and clean-booting, the setup logs name the exact blocker. Check C:\$WINDOWS.~BT\Sources\Panther\setuperr.log for the failing driver or file, then update or remove that specific item. You can also submit your error to us for a tailored fix.
