0xC1900101
Upgrade rolled back
What it means
A Windows feature upgrade failed and rolled back. The part after the dash tells the phase; almost always a driver is to blame.
Common causes
- Incompatible drivers (storage, network, antivirus)
- Too little free disk space
- Extra USB devices plugged in
How to fix it
- Free at least 30 GB on C:.
- Unplug everything except keyboard, mouse and screen.
- Uninstall third-party antivirus for the upgrade.
- Update the graphics, chipset and network drivers from the maker's site (NVIDIA, AMD, Intel or your board vendor), not from a driver-updater tool.
- Try the upgrade again with the Installation Assistant.