How to fix Windows upgrade error 0xC1900101 - 0x30018?

Error 0xC1900101 - 0x30018 means a Windows upgrade failed during its first restart and Setup put your old Windows back. Microsoft's own explanation is that a device driver stopped responding to setup.exe. Unplug everything except the mouse, keyboard and display first, then update the drivers Device Manager flags.

Facts checked on 15 October 2026. Steps written for Upgrades from Windows 10 22H2 to Windows 11, and Windows 11 feature updates to 25H2 and 26H2.

What 0xC1900101 - 0x30018 means

Windows Setup reports a failed upgrade with two codes joined by a dash. Microsoft calls the first one the result code, which says what went wrong, and the second one the extend code, which says in which phase and operation it happened.

The full text on the screen reads: We couldn't install Windows 10. We've set your PC back to the way it was right before you started installing Windows 10. 0xC1900101 - 0x30018. The installation failed in the FIRST_BOOT phase with an error during SYSPREP operation.

Why the upgrade fails with 0xC1900101 - 0x30018

Microsoft gives one cause for this pair, a driver that stops responding, and lists the same first steps for all six 0xC1900101 codes it documents. The ranking below follows Microsoft's order of mitigations. Each cause points to a fix.

Where setupapi.dev.log and SetupDiag show the failing driver

You do not need the logs for Fix 1. Read them when the error comes back, because they name the driver. After a rollback, Setup keeps its files in the hidden folder C:\$Windows.~BT\Sources\Rollback. Microsoft lists three files there that help with 0xC1900101.

Microsoft also recommends SetupDiag, its free tool that reads the Setup logs and names the reason for an upgrade failure. Fix 3 shows how to use both.

How to fix Windows upgrade error 0xC1900101 - 0x30018

Fix 1 and Fix 2 are Microsoft's first mitigations for this code and solve it for most readers. Fix 3 finds the exact driver when you do not know it. Fix 4 to Fix 6 remove what loads extra drivers or blocks space. Fix 7 and Fix 8 come last because they rarely cause this code.

Fix 1. Unplug every device except the mouse, keyboard and display

5 minutes, plus the upgradeNo riskEveryone, and first of all PCs with USB drives, a dock, a card reader, a printer or a second monitor attached.

Setup installs drivers for every connected device during the first restart. Microsoft's first mitigation for 0x30018 is to disconnect all peripherals except the mouse, keyboard and display, because one of their drivers is the usual one that stops responding.

1. Shut down the PC.
2. Unplug USB flash drives, external hard drives, memory cards, printers, scanners, webcams, headsets, game controllers and USB hubs.
3. If the laptop sits in a docking station, undock it. Connect the charger directly.
4. Disconnect a second monitor. Keep one display, the mouse and the keyboard.
5. Start Windows and run the upgrade again: Settings > Windows Update > Check for updates, or setup.exe from the installation media.
6. When the upgrade finishes, plug the devices back in one at a time.

Fix 2. Update or remove the drivers that Device Manager flags

15 to 30 minutesLow riskDevice Manager shows a yellow exclamation mark, or the PC has not had driver updates for a long time.

Microsoft's second mitigation for 0x30018 is to get updated drivers from the hardware vendor. Its support page for 0xC1900101 adds two checks: run Windows Update a few times for driver updates, and fix any device that Device Manager marks with a yellow sign.

1. Open Settings > Windows Update, select Check for updates and install everything. Repeat until nothing new appears.
2. Open Advanced options > Optional updates and install the driver updates listed there.
3. Right-click Start and select Device Manager. Expand each category and look for a yellow exclamation mark.
4. Right-click a flagged device and select Update driver. If no newer driver is found, select Uninstall device for a device you do not need during the upgrade.
5. On the PC or motherboard maker's support page, get the newest chipset, storage, display and network drivers for your model and install them.
6. Restart and run the upgrade again.

Step by step, with screenshots of Device Manager: Update, roll back or reinstall a driver

Fix 3. Find the failing driver in setupapi.dev.log or with SetupDiag

15 minutesNo riskThe upgrade failed again after Fix 1 and Fix 2 and you want the name of the driver.

For extend code 0x30018, Microsoft names the device install log in the Rollback folder as the helpful file. Its last entries show which driver Setup was installing when it stopped, so you fix one device instead of guessing.

1. Press Win + R, paste C:\$Windows.~BT\Sources\Rollback\setupapi and press Enter. If the folder is missing, a cleanup removed it, so run SetupDiag instead (step 6).
2. Copy setupapi.dev.log to your desktop and open the copy in Notepad.
3. Press Ctrl + End to go to the end of the file. The last device entries come from the failed attempt.
4. Look for lines that start with !!! or contain failed, and note the device name and the .inf file just above them.
5. Update that driver from the device maker, or uninstall the device in Device Manager, then run the upgrade again.
6. If the log does not help, download SetupDiag from Microsoft, run it in Terminal (Admin) and read SetupDiagResults.log in its folder.

Run SetupDiag from its folder in an administrator terminal:

SetupDiag.exe /Output:C:\SetupDiag\Results.log

Fix 4. Uninstall non-Microsoft antivirus and disk encryption software for the upgrade

15 minutesLow riskA non-Microsoft antivirus, firewall suite or disk encryption tool is installed.

Security and encryption software installs filter drivers that load early in the first restart. Microsoft's support page for 0xC1900101 says to remove third-party security software and lets Microsoft Defender protect the PC in the meantime.

1. Make sure you have the installer and the licence key or account of the security product.
2. Uninstall it from Settings > Apps > Installed apps, or with the maker's own removal tool if it offers one.
3. Restart. Microsoft Defender turns on by itself when no other antivirus is installed.
4. Run the upgrade again.
5. When the new version runs, install the newest release of your security product again.

Step by step for removing a program: Uninstall a program or app in Windows. For disk encryption from another maker, decrypt the drive with that tool first, as its maker describes, because removing it while the drive is encrypted can lock your data.

Fix 5. Free up at least 20 GB on drive C

10 to 20 minutesLow riskDrive C has less than 20 GB free, or the error alternates with 0xC190020e.

Microsoft's first step for all 0xC1900101 codes is enough free space: 16 GB for 32-bit Windows and 20 GB for 64-bit. With too little room, Setup can fail at any later step.

1. Open Storage settings. Select Start > Settings > System > Storage. The top of the page shows how full the drive is and what uses the space.
2. Open Cleanup recommendations. Under Storage management, select Cleanup recommendations.

   

3. Clean up what Windows suggests. Open each group (Temporary files, Large or unused files, Files synced to the cloud, Unused apps), check the items you do not need and select Clean up in that group.

   

4. Delete more temporary files. Go back to Storage and select Temporary files. Windows lists the types it can remove with their size. Check the ones you do not need and remove them. Leave Downloads unchecked unless you have checked that folder.

These steps were written for Windows 11 (screenshots: 26H2). The full page with the other versions and what each result means: Free up disk space and delete temporary files

• Check the result in File Explorer > This PC: drive C should show 20 GB free or more.
• If space is short and the PC has a USB port, Microsoft notes that Setup can use an external USB drive of at least 8 GB, formatted NTFS, for the backup of the old Windows. Plug it in only for this, after Fix 1.

Fix 6. Run the upgrade from a clean boot, with updates downloaded during Setup

20 minutes, plus the upgradeLow riskFix 1 to Fix 5 are done and the PC has many startup programs or background services from other makers.

Microsoft says a rollback caused by driver conflicts can be solved by running Setup with a minimal set of drivers and startup programs, which a clean boot gives you. It also asks to accept "Download and install updates (recommended)" so Setup fetches new drivers.

1. Open System Configuration. Select Search on the taskbar, type msconfig and select System Configuration from the results.
2. Hide Microsoft services. On the Services tab, select the Hide all Microsoft services check box. Only services from other companies stay in the list.

   

3. Disable the remaining services. Select Disable all, then select Apply.
4. Open Task Manager. On the Startup tab of System Configuration, select Open Task Manager.

   

5. Disable the startup apps. On the Startup apps tab in Task Manager, select each item whose status is Enabled and select Disable. Write down or take a screenshot of the items you disable: you need the list to turn them back on.

   

6. Confirm the changes. Close Task Manager. On the Startup tab of System Configuration, select OK.
7. Restart and test. Restart the PC. Windows now starts in a clean boot environment: try again the thing that failed (run the app, install the update, uninstall the program).

These steps were written for Windows 11 25H2 and 26H2. The full page with the other versions and what each result means: How to perform a clean boot in Windows

1. In the clean boot, download the ISO from Microsoft's Download Windows 11 page, right-click it and select Mount.
2. Double-click setup.exe on the new drive.
3. When Setup asks about updates, choose to download and install updates. Microsoft's wording is "Download and install updates (recommended)", and newer media words it differently.
4. Keep files and apps, and let the upgrade run.
5. After the upgrade, undo the clean boot as the clean boot procedure describes.

Fix 7. Repair disk errors and system files

20 minutes to several hoursLow riskThe PC crashed or lost power often, or the error came back after all fixes above.

Microsoft's list for 0xC1900101 ends with repairing hard drive errors and restoring system files. File system damage or a broken component store can make Setup fail at the first restart, even with good drivers.

1. Right-click Start and open Terminal (Admin).
2. Type chkdsk /f C: and press Enter. Answer Y to run the check at the next restart, then restart.
3. After the restart, open Terminal (Admin) again and run DISM.exe /Online /Cleanup-image /Restorehealth.
4. Run sfc /scannow when DISM has finished, restart and try the upgrade again.

With screenshots: Check a disk for errors (chkdsk) and Run DISM and SFC to repair Windows system files.

Fix 8. Update the BIOS or UEFI firmware

15 to 30 minutesRead the warningThe PC maker lists a newer BIOS for your model and every other fix failed.

Microsoft lists BIOS updates among the mitigations for its 0xC1900101 codes 0x20004 and 0x4000D. Old firmware can make a controller misbehave when the new Windows loads its drivers at the first restart.

1. Press Win + R, type msinfo32 and press Enter.
2. Note System Model, BaseBoard Product and BIOS Version/Date.
3. On the PC or motherboard maker's support page for that model, compare the newest BIOS with yours.
4. If a newer one exists, follow the maker's own instructions to install it.
5. Start Windows and run the upgrade again.

If error 0xC1900101 - 0x30018 is still there

When the upgrade still rolls back with every device unplugged and current drivers, the logs decide the next step. Read setupapi.dev.log and the SetupDiag result as in Fix 3 before you try again, because each new attempt replaces them.

• What to send to support: both codes, the Windows version you upgrade from and to, and how you started the upgrade.
• Attach setupapi.dev.log, setupact.log, setuperr.log and the SetupDiag result.
• Name the hardware: PC model, BIOS version and any device the log mentions.

How to keep 0xC1900101 - 0x30018 from coming back

Windows 10 left support on 14 October 2025. Microsoft says it no longer provides free software updates, technical help or security fixes for it, and recommends moving to Windows 11. If the upgrade fails on a Windows 10 PC, these fixes are the way to get there.

Frequently asked questions

What does error 0xC1900101 - 0x30018 mean?

It means a Windows upgrade failed during its first restart and Setup restored your previous Windows. Microsoft describes the pair as "A device driver has stopped responding to setup.exe during the upgrade process." The first code, 0xC1900101, is the generic rollback code. The second code, 0x30018, says the failure happened in the FIRST_BOOT phase during the SYSPREP operation. Your files and apps stay as they were. Start by unplugging devices and updating drivers.

What is error code 0xC1900101 on its own?

0xC1900101 is the result code MOSETUP_E_SETUP_PLATFORM. Its text is "The Setup Platform has encountered an unspecified error". Microsoft calls it a generic rollback code that usually points to an incompatible driver, and says it can appear at any stage of the upgrade except the first, downlevel phase. Windows Update often shows only this part. The second code, if you can find it in the Setup logs, says when it failed. For every 0xC1900101 code Microsoft recommends the same first steps: free space, Windows Update, drivers, unplugging hardware.

Is 0x30018 an error by itself?

No. 0x30018 is only the extend code, the second half of the error. In Microsoft's table, the first digit 3 is the FIRST_BOOT phase and the last two digits, 18, are the SYSPREP operation. It tells you when the upgrade failed, not why. The reason is in the first code, 0xC1900101, and in the logs. Microsoft also notes that its table of extend codes was written for Windows 10 version 1607 and might change, but this pair is still listed with the same meaning.

How do I fix 0xC1900101 - 0x2000c?

Use the same first steps, because Microsoft gives the same mitigations for it: disconnect every device except the mouse, keyboard and display, get updated drivers from the hardware maker, and accept downloading updates at the start of Setup. The difference is the moment. 0x2000c fails in the earlier SafeOS phase while the Windows image is applied, and Microsoft adds that disk corruption can cause it. So run chkdsk (Fix 7) earlier for that code.

What are 0xC19001e1 and 0xC1900104?

They are other Setup result codes, not variants of 0x30018. Microsoft lists 0xC19001e1 as MOSETUP_E_PROCESS_SUSPENDED, "The installation process was suspended", and 0xC1900104 as MOSETUP_E_PROCESS_TIMEOUT, "The installation process did not complete within the required time limit." Both mean Setup itself was stopped or ran too long. Keep the PC plugged in, awake and online during the upgrade, then run it again. If a driver hangs Setup, Fix 1 and Fix 2 still apply.

What does 0xC190020e mean?

0xC190020e is MOSETUP_E_INSTALLDISKSPACE_BLOCK: the PC does not have enough free space to install the upgrade. Microsoft asks for 16 GB free for 32-bit Windows and 20 GB for 64-bit Windows. Free space on drive C with Storage settings and Disk Cleanup, as in Fix 5, and run the upgrade again. Microsoft adds that Setup can use an external USB drive of at least 8 GB, formatted NTFS, to back up the old Windows when space is short.

Will I lose my files when the upgrade rolls back?

No, not in the normal case. The message says Windows set your PC back to the way it was right before the upgrade started, and the rollback restores your previous Windows with its files, apps and settings. Still, back up important files before the next attempt, because each attempt rewrites system files and restarts several times. A backup also protects you if you later update the BIOS or remove encryption software.

Why does Windows Update keep offering the same failed upgrade?

Because the PC still qualifies for the feature update, and Windows Update retries it until it succeeds or you pause updates. Each retry hits the same driver, so the same 0xC1900101 comes back. Pause updates in Settings > Windows Update while you work through the fixes, then resume. Running setup.exe from a Microsoft ISO after a clean boot, as in Fix 6, gives you more control over the attempt.

Can a driver updater program fix this error?

Microsoft's advice is to get updated drivers from the hardware vendor and through Windows Update. Those two sources give you the drivers the PC maker tested for your model. A tool that installs drivers from other places can add the kind of driver that stops responding at the first restart. If you do not know which driver is at fault, read setupapi.dev.log or run SetupDiag (Fix 3) instead of updating everything.

This page is about 0xC1900101 - 0x30018: what about other languages?

The error codes are the same in every language, so this guide applies to messages such as installationsfel - 0xc1900101 or errore 0xc1900101. Only the text around the code is translated. Look for the two codes on your screen or in Settings > Windows Update > Update history, and use the fixes in the same order. Readers who wrote a search in another language without a code should first find the code in Update history.