Fix: Installation Failed in the SAFE_OS Phase Error (0xC1900101)

If you’re trying to reinstall or upgrade Windows 10 and see the message “We couldn’t install Windows 10 – The installation failed in the SAFE_OS phase with an error during BOOT operation (0xC1900101-0x20017)”. This error is common on older laptops like HP 15-bs0xx or systems running in Legacy BIOS mode, and it usually points to a boot configuration or driver conflict.

Fix: Installation Failed in the SAFE_OS Phase with an Error During BOOT Operation (0xC1900101-0x20017)

Why This Error Happens

The code 0xC1900101-0x20017 usually appears because of one or more of the following:

Incompatible BIOS or incorrect boot mode (Legacy instead of UEFI)
Outdated or corrupted drivers (graphics, storage, or chipset)
Faulty or incomplete bootloader
External devices interfering with setup
Antivirus or third-party tools blocking the OS installer

Fix: Windows Installation Failed in SAFE_OS Phase

Follow these steps in order. Don’t skip any unless you’ve already completed it.

Step 1. Check and Change BIOS Boot Mode

Restart your PC and press F10 (for HP) or Del/F2 to open BIOS.
Navigate to System Configuration → Boot Options.
If the system shows Legacy, change it to UEFI.
Save and exit (usually F10).

Note: If your disk is using MBR partition style, you’ll need to convert it to GPT before switching to UEFI.
Run this command in Command Prompt (Admin):

mbr2gpt /convert /allowfullos

Step 2. Disconnect External Devices

Unplug all unnecessary hardware:

USB drives
Printers and external HDDs
Game controllers or dongles

Only keep the keyboard, mouse, and power cable connected.

Step 3. Disable Antivirus and Security Tools

Before reinstalling Windows:

Uninstall third-party antivirus or cleanup apps (like Avast, McAfee, CCleaner).
Disable BitLocker or any system encryption tools.

These often interfere with the Windows installer during the SAFE_OS phase.

Step 4. Update BIOS and Drivers

Even if your BIOS is recent (e.g., Insyde F.76, July 2024), reinstalling it can help clear corrupted firmware data.

Visit the official HP Support Page → search for HP Laptop 15-bs0xx, then download and install:

BIOS Update
Intel Chipset Driver
Intel Rapid Storage Technology (RST)
Graphics Driver

Reboot after installation.

Step 5. Create a Clean Windows 10 Installation USB

Go to the Microsoft Media Creation Tool page.
Download the tool and create a bootable USB (minimum 8 GB).
Boot from USB → choose Custom Install.
Delete all partitions from the target drive → click Next to install on the unallocated space.

This ensures you start fresh, removing all corrupt partitions or boot entries.

Step 6. Repair the Bootloader (If the Error Persists)

If you still get a black screen or loop, try repairing the boot configuration manually.

Boot from the Windows 10 USB.
Select Repair your computer → Troubleshoot → Command Prompt.
Run the following commands one by one:

bcdboot C:\Windows /s C:
bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd

Restart your PC and attempt installation again.

Step 7. Adjust SATA Mode in BIOS (Optional)

If your BIOS includes Storage Controller Mode, toggle it:

Switch AHCI ↔ IDE, then retry the installation.

This fixes cases where Windows setup fails due to incompatible storage drivers.

Step 8. Wipe the Disk and Reinstall (Last Resort)

If nothing works and you still hit the same error:

Boot from the USB installer again.
Choose Repair → Troubleshoot → Command Prompt.
Type the following:

diskpart
list disk
select disk 0
clean
exit

Close the window and restart the Windows setup.

This will erase everything from your primary disk — back up important files before doing this.

If your laptop has Intel i3-6006U or similar older CPUs, use Windows 10 22H2 (Build 19045) — newer Windows 11 builds may not install correctly in Legacy mode.

Read More:

The error 0xC1900101-0x20017 – The installation failed in the SAFE_OS phase is typically fixable by correcting your BIOS mode and driver setup. Once you’ve updated drivers, switched to UEFI, and used a clean installation USB, Windows 10 should install smoothly without boot errors.

Fix: Installation Failed in the SAFE_OS Phase with an Error During BOOT Operation (0xC1900101-0x20017)