# Windows 11 update keeps failing at the same percentage, then rolls back

Source: https://forum.geekwithlaptop.com/thread/windows-11-update-keeps-failing-at-the-same-percentage-then-rolls-back/
Site: Geek With Laptop Forum, category Windows laptops
Published: 2026-10-17. Updated: 2026-10-18. Replies: 7.

## Question by Raul M., 2026-10-17

I do helpdesk for a living and this one is beating me, which is embarrassing. It is my own Windows 11 laptop. The monthly cumulative update downloads fine, goes through "Preparing", reboots, and then sits at 74 percent on the blue screen for a long time. After about half an hour it says "We could not complete the updates, undoing changes" and rolls back. Same percentage, every attempt, five attempts now.

What I have already tried: the Windows Update troubleshooter, stopping the update service and clearing the SoftwareDistribution folder, sfc /scannow and DISM /Online /Cleanup-image /Restorehealth (both came back clean), plenty of free disk space, and date and time set correctly. Antivirus is just the built-in one.

Event Viewer shows an install failure with an error ending in C1900101. I know that code can mean a driver conflict, but I have not narrowed down which one. Anyone seen a repeatable stall at a fixed percentage and found the cause?

## Reply 1 by Dmitri, 2026-10-17

A fixed percentage on rollback is the machine telling you which stage it chokes on, so it is repeatable and therefore findable. Look at the setup logs under C:\$WINDOWS.~BT\Sources\Panther (setuperr.log and setupact.log) and search for the last driver or operation mentioned before the rollback. It is dull reading, but it usually names the culprit.

## Reply 2 by Tyler B., 2026-10-17

Easy fix. Delete everything in C:\Windows\SoftwareDistribution right away while the update is stuck, then restart and run it again. Also turn off Windows Update in services for good, so it stops trying and failing. Problem solved, no more error.

## Reply 3 by Dmitri, 2026-10-18

@Tyler B. the first part is close to what Microsoft's own steps say, but order matters: stop the Windows Update service first, then clear the folder, then start it again. And disabling Windows Update permanently is a bad idea, you stop getting security fixes. Fix the cause instead.

## Reply 4 by Raul M., 2026-10-18

@Dmitri that was the way in. setuperr.log points at a driver for a network adapter that is several versions behind, which fits the C1900101 error. I should have gone to the logs before the third retry.

## Reply 5 by Grace O., 2026-10-18

Before you go into logs, unplug everything: dock, external drives, USB hubs, a second monitor. We had a work laptop that failed the same way every month until the dock was disconnected, then it installed on the first try. It is a two minute test and it has fixed more updates for us than anything fancy.

## Reply 6 by Owen P., 2026-10-18

C1900101 is almost always a driver, and on older machines the usual suspects are the display driver, the Wi-Fi or Bluetooth driver, and storage controller drivers. Get the current ones from the laptop maker's support page, not from a driver tool. Also check the disk. A failing SSD can stall an update at the same spot when it hits a bad block, so run chkdsk /f on C: and look at the drive's health status.

## Reply 7 by Raul M., 2026-10-18

@Grace O. I did that too, no dock was attached but I had a USB Wi-Fi adapter plugged in from a test. I removed it, uninstalled the old network adapter driver in Device Manager, restarted, and the update finally completed on the next attempt. So it was the driver, not the disk.

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Cite as: Geek With Laptop Forum, "Windows 11 update keeps failing at the same percentage, then rolls back", https://forum.geekwithlaptop.com/thread/windows-11-update-keeps-failing-at-the-same-percentage-then-rolls-back/, accessed 2026-11-10.