How to factory reset Microsoft Surface Model number 1866 with Windows Pro 10 installed without recovery key.

Performing a Clean Windows Installation on Your Surface

You can repurpose the hardware by installing a fresh copy of Windows. Follow these steps:

1. Prepare Installation Media

Using another computer, visit microsoft.com to download the Windows 10 Media Creation Tool. Use it to create a bootable USB drive (you'll need a USB drive with at least 8GB of storage).

https://www.microsoft.com/en-in/software-download/windows10

2. Boot Your Surface from USB

Insert the USB drive into your Surface 1866. Power on the device while holding the Volume Down button to access the boot menu. Select your USB drive from the boot options.

3. Remove Existing Partitions

When the Windows installer appears, select "Custom: Install Windows only (advanced)." You'll see a list of existing partitions—delete each one. This completely removes the previous company configuration, including any encryption.

4. Complete the Installation

After deleting the partitions, Windows will automatically create new ones and begin the installation process. This typically takes 20-30 minutes.

5. Configure Your Device

Once installation finishes, you'll be guided through the initial setup where you can create your own local account or sign in with your personal Microsoft account. You'll have full administrator access to the device.

Hi Jimmy Holtschlag,

Welcome to Microsoft Q&A!

I understand that you want to reset the old Surface Model 1866. However, without the recovery key (assuming BitLocker key), it might be tricky. Let's try to boot from with Recovery Image to see if it can override the current system:

1. You'll need another working device and a bootable media (e.g. USB)
2. Plug the USB into PC > Open File Explorer > right-click the USB drive
3. Choose Format > select FAT32 as the file system type
4. Enter a Volume label (e.g. RECOVERY) > Start
5. Visit the page to Download the recovery image for your Surface
6. Sign in > Select your device:
   1. From my finding, Surface1866 is Pro 7 - but choose your correct device.
   2. Enter its serial number (you can find it following on-screen instruction)
7. Confirm and download the recovery image > save it to your PC.
8. Right click the downloaded package > Extract > Extract all.
9. Select the USB drive you formatted earlier for the location.
10. Shutdown the Surface > Plug the USB recovery drive in.
11. Hold the volume-down button + press the power button one
12. When the Surface logo appears, release the volume-down button
13. Surface will start the recovery software on the USB recovery drive
14. When prompted, choose your language options and keyboard layout
15. Select Troubleshoot > Recover from a Drive > Fully clean the drive > Recover.

Note: As the suggestion is for factory reset, your drive will be wiped clean.

I hope the steps above were clear enough. If there's anything not appearing as expected, let me know!

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