If you're trying to update or install Windows and you get the dreaded message “Installation error in the FIRST_BOOT phase” with codes like 0xC1900101 - 0x30018 or similar situations, it's normal to end up feeling a bit desperate. Many users have been stuck on older builds of Windows 10 for months or can't even make the jump from Windows 7 or 8.1, watching the installation revert over and over again.
This type of failure is often accompanied by blue screens, looping restarts, and messages like “We have reverted your PC to its previous state”Although it may seem like a mysterious problem, it is almost always related to drivers, antivirus, third-party programs or even minor errors in system files. Let's calmly break down exactly what this FIRST_BOOT error means, what its most common causes are, and how you can fix it step by step.
What does the error in the FIRST_BOOT phase mean?
During a Windows 10 or 11 update or installation, the system goes through several internal phases, and when something goes wrong, a message like this may appear. “The installation failed in the FIRST_BOOT phase with an error during the SYSPREP operation” or variations such as SECOND_BOOT or MIGRATE_DATA.
In many cases the error is accompanied by rollback codes like 0xC1900101which indicate that Windows has detected a serious problem and has decided undo changes to leave the system as it was before the update attempt.
These are some of the codes that are often associated with this FIRST_BOOT problem or other phases of the initial boot process after installation:
- 0xC1900101 - 0x30018 – Error in the FIRST_BOOT phase during the SYSPREP operation.
- 0xC1900101 - 0x40017 – Error in the SECOND_BOOT phase, also related to the first boot after installation.
- 0xC1900101 – 0x3000D – Error in the FIRST_BOOT phase during the MIGRATE_DATA operation.
- Other codes from the same family: 0xC1900101 – 0x2000C, 0x20004, 0x20017, 0x30018, 0x40021…
Even if the number changes, all these codes 0xC1900101 They have something in common: they indicate a compatibility issue or driver failure or with components that interfere with critical Windows startup and configuration phases during installation.
Main causes of the FIRST_BOOT error (0xC1900101)
The most frustrating part is that the error message doesn't clearly tell you what went wrong, but from thousands of real-world cases we know that in most situations the failure comes from problematic drivers, antivirus, or highly intrusive software.
These are them most frequent causes which can trigger an error in the FIRST_BOOT or SECOND_BOOT phase with codes 0xC1900101:
Outdated or incompatible drivers
The number one culprits are, by far, the incompatible driversThis could be the graphics card, network card, storage controllers, WiFi adapters, advanced USB devices, or even fiber controllers like those from QLogic in server environments.
In Windows 10 and Windows Server 2019, there have been many cases where a single driver, for example a QLogic storage miniport In older versions, it caused a blue screen during the update. Microsoft provides a tool called SetupDiag.exe which allows you to analyze the installation logs and pinpoint exactly which driver is causing the failure.
Antivirus and security programs
Another very common source of headaches are the third-party antivirus and security suitesThis type of software integrates at a low level with the system, monitors processes, blocks changes to critical files, and sometimes interprets Windows updates as a potential threat.
Microsoft has explicitly stated that many errors such as 0xC1900101 - 0x30018 They are due to incompatibilities with antivirus or protection toolsEven if you disable the antivirus, there may still be services, drivers, and registry entries that interfere with the installation.
Third-party software and highly intrusive programs
It's not just antivirus software that can cause problems. Certain backup applications, encryption programs, banking software, optimization suites, or tools that add system-level filters (for example, software like) can also cause issues. Acronis True Image, Trusteer Rapport and similar) may clash with the update process.
These types of programs install controllers, services and filters that are loaded at startup, and if they are not prepared for the new version of Windows, they can easily cause an error in the FIRST_BOOT phase or during data migration.
Damaged system files or a previously corrupted installation
If the system you are trying to update is already running corrupted system filesDue to disk errors or previous problems with Windows Update, the update may fail just as Windows attempts to apply in-depth changes.
In these cases, internal tools such as sfc / scannow and the commands DISM /Online /Cleanup-image /ScanHealth y / RestoreHealth They help repair the Windows image before attempting the update again.
Insufficient disk space
It's not the most exotic cause, but it's still common: a system unit with little free space It can cause the installation to stop halfway through and end up reverting the changes with a code 0xC1900101.
Windows 11 needs at least 64 GB of system space and additional space to download and unpack the update files; Windows 10 typically requires at least 16 GB for the system, plus plenty of free space to work comfortably.
Network problems or corrupted download
The update is downloaded via the internet and, if the connection is unstable, it can end up failing. corrupted installation filesIn some cases, the Windows Update cache itself becomes corrupted and causes recurring failures.
That's why it's recommended to delete the folder software distribution when there are repeated update errors, thus forcing Windows to download the packages from scratch.
Outdated BIOS and firmware
An Old BIOS or unupdated firmware Complications on the motherboard, disk controllers, or adapters like QLogic HBAs can cause serious incompatibilities with newer versions of Windows. Before updating, it's advisable to check a essential hardware checklist to check compatibility and recommended versions.
In some environments, it has been observed that even after updating the driver, the update would fail again until the system was updated. BIOS, HBA firmware, and other componentsThis point is delicate and should be done with specific information from the manufacturer.
Check Windows version and computer compatibility
Before diving into the repair, it's very useful to know exactly Which version of Windows are you using? And what build do you have installed, especially if you're part of the Insider program or stuck on an older build like 1709.
To View this information you can:
- Pulsar Windows + R, to write winver and press OK.
- Check the edition (Home, Pro, Server, etc.), the version, and the build number.
It is also important to identify make and model of the equipment (especially on laptops like the Lenovo G50-30 and similar) to check on the manufacturer's website for official compatibility, recent BIOS and updated drivers for the version of Windows you want to install.
Preparing the system: basic cleaning and native tools
Before making more aggressive changes, it's worth clearing the ground as much as possible using the built-in windows toolsThis helps to repair damaged installations and, incidentally, to rule out simple problems.
Repair system files with SFC and DISM
The commands CFS and DISM They are designed to locate and repair corrupted system files, as well as errors in the Windows image. It is recommended to run them with an internet connection and from a console with administrator privileges.
- Balance Windows + X and open Command Prompt (Admin) o Windows PowerShell (Administrator).
- Write sfc / scannow and press Enter; wait for it to finish (it may take several minutes).
- Then run DISM.exe / Online / Cleanup-image / Scanhealth and press Enter.
- Next, he launches DISM.exe / Online / Cleanup-image / RestoreHealth and wait for it to finish.
It is very important to let each command finish completely before launching the next one, and upon completion Restart the system to apply the changes, and in specific cases use bootrec.exe can help repair the starter.
Run the Windows Update troubleshooter
When the failure is related to the update itself, the windows update troubleshooter It can detect and correct issues with the cache, services, or internal components of Windows Update.
From Windows 10, you can access the solver So:
- OPEN Settings > Update & security > Troubleshoot.
- Walk into Additional troubleshooters and run Windows Update.
- Apply the suggested corrections and restart your PC.
If it tells you that no problems found But the errors persist; it will be necessary to continue with more specific methods.
Update, review, or remove problematic drivers
Since the 0xC1900101 codes almost always point to drivers, one of the key actions is to check the Device administrator looking for corrupted drivers or very old versions that may conflict with the new version of Windows.
To this end, Windows 10 or 11:
- Right-click the Start button and enter Device administrator.
- Check the list for devices with a yellow warning icon.
- In each one, right-click and select Update Driver.
- Choose the option Search for drivers automatically so that Windows can try to locate the latest version.
If a device is still giving you trouble, you can try Disable device temporarily or even Uninstall device before attempting the update, knowing that afterwards you will have to reinstall your drivers.
In more advanced environments, such as servers with specific controllers, it is useful to extract the installation logs from the setup directories and analyze them with the official tool SetupDiag.exe from Microsoft. This utility examines the update logs and can pinpoint the specific driver causing the blue screen.
In the case of QLogic controllers, for example, several updates have been released for their miniport driver (versions 9.2.9.x, 9.3.3.20, 9.4.1.20, 9.4.4.20…) in response to compatibility issues with Windows Server 2016/2019, and upgrading to the latest available version has fixed FIRST_BOOT errors in many scenarios.
Clean the driver store and update BIOS/firmware
Even if you install newer driver versions, the system may still retain older versions in the DriverStoreAnd in some situations, that again causes update failures.
It is possible to access the folder %WINDIR%\System32\DriverStore and use specialized tools to view and remove old driver packages that should no longer be used. It's important to be precise to avoid deleting anything critical, so this is a more advanced measure. Tools such as Windows Performance Recorder They can help detect bottlenecks related to drivers and hardware.
Furthermore, if the error persists after updating the drivers, it is highly recommended to check, and if indicated by the manufacturer, update the BIOS and firmware of the computer, the motherboard, and the HBAs or storage controllers involved. Many manufacturers have released new versions specifically to improve compatibility with the latest versions of Windows.
Disable antivirus, security programs, and unnecessary peripherals
In parallel For controllers, another basic strategy is reduce to the minimum Things that may interfere with the installation.
Remove conflicting antivirus and third-party software
The general recommendation is completely uninstall any third-party antivirus software and security suites before attempting to update, instead of simply disabling them.
To remove the antivirus:
- Open the Control Panel > Uninstall a program.
- Locate the antivirus or security suite and click on Uninstall / Change.
- Follow the wizard to the end and restart your computer.
This same approach can be applied to particularly intrusive programs or suspicious (complex backup software, banking tools that install filters, aggressive optimizers, etc.). If you started having problems right after installing a particular application, it's a good idea to temporarily uninstall it.
Disconnect external devices
The fewer devices Windows has to manage during installation, the better. This is advisable. Disconnect all peripherals that are not essential:
- Printers, scanners, external USB drives, hubs, cameras, etc.
- Special adapters (capture cards, external sound cards…).
Ideally, only leave them connected keyboard, mouse and monitorAnd if you're using WiFi, try switching to a wired connection. Ethernet cable to reduce risks during unloading and installation.
Perform a clean boot to avoid software interference
If you suspect that third-party programs have been creeping in from the start and complicating the update, a Clean boot It allows Windows to start with only the essential services and drivers.
To prepare a clean boot on Windows 10/11:
- Balance Windows + R, writes msconfig and press Enter.
- In the Services, Mark Hide all Microsoft services and then click on Disable all.
- Open the Task Manager and tab Home Disable all non-essential applications.
- Restart the computer.
In this mode, the system will start with only the essentialsThis greatly reduces the likelihood of a third-party program causing the 0xC1900101 code during the FIRST_BOOT phase.
Free up disk space and clean up update remnants
For the update to have room for maneuver, it is essential to have enough free space on the system drive (usually C:). If you're really short on gigabytes, the first thing to do is make some space.
Some useful actions for gain space:
- Delete Temporary files, contents of the Trash and downloads you no longer need.
- Delete the folder windows.old if you no longer plan to revert to the previous version.
- Uninstall programs you don't use and clean up their residual data.
- Increase the size of the system partition or, if applicable, transfer programs and files to another unit.
When many failed update attempts have accumulated, deleting or renaming the folder can help. software distribution (with Windows Update services stopped) to force a clean download of the packages.
Installation using external media and activation problems
If Windows Update is still stuck after all that, some users have managed to break out of the FIRST_BOOT error loop by performing the update from a ISO image or installation usb Created with Microsoft's media creation tool.
This method bypasses some of the Windows Update logic, but it also has its drawbacks: if the underlying incompatibility hasn't been resolved (driver, antivirus, BIOS, etc.), the problem may recur. Furthermore, care must be taken with the windows activationUsing public keys circulating on the internet or "miracle" serial numbers is illegal and can leave the system without a valid license.
If you're doing a clean install because nothing else works, it's always recommended to use a original license or the key associated with your device in the Microsoft account, instead of resorting to generic keys that only serve to complicate your life in the medium term.
When to consider a "Fresh Start" or resetting your PC
On computers that have accumulated programs, driver remnants, version changes, and errors over the years, sometimes there's no other option but to consider a complete PC reset or a clean installation.
In Windows 10 you have the option "Reset this PC", which enables:
- Keep your personal files but reinstall Windows from scratch.
- Remove everything, including data and applications, to leave the device as if it were brand new.
Accessed from Settings > Update & security > Recovery and clicking on Contac us within “Reset this PC”. It's a drastic measure, but if the system is severely damaged, it can be the quickest way to install the latest version without carrying over old problems.
Best practices to prevent the mistake from happening again
Once you have successfully completed the FIRST_BOOT phase of your Windows installation, it is worth following a few steps. good practice to avoid encountering 0xC1900101 again in future major updates.
- Always keep enough free space in the system unit, especially before large updates.
- Check periodically that the main drivers (graphics, network, storage, chipset) are updated from the official websites.
- Run sfc / scannow and, if necessary, DISM periodically when you notice strange behavior.
- Avoid installing software of dubious origin or tools that promise to "optimize" Windows by modifying deep settings without control.
- Temporarily disable or uninstall the third party antivirus during major system updates.
By following these guidelines, along with the solutions above, future Windows updates are much more likely to install smoothly and without the annoying error message appearing again during the FIRST_BOOT phase with code 0xC1900101.
These types of Windows update errors are usually the result of several factors: a outdated controller Here, a jealous antivirus; there, little free space; or a BIOS forgotten in an old version.
By carefully checking drivers, cleaning the system, uninstalling conflicting software, and, when necessary, updating firmware or even reinstalling from scratch, you can get Windows to complete the installation without reverting changes or showing the famous FIRST_BOOT failure again. Share this information so more users can resolve the FIRST_BOOT error in Windows.