If your Surface Laptop is a prototype labelled “NOT FOR SALE” with a “CoreOS” sticker, the problem may be that it is an engineering or pre-release device rather than a retail Surface. In that case, Microsoft's public recovery website may not recognise its serial number.
Try: Surface Recovery Image Download
Sign in and try the serial number shown in Surface UEFI or Windows System Information. If it still fails, don't repeatedly try unrelated retail models.
Contact Microsoft Surface engineering or your device's original provider
Explain that the device is a prototype marked Not for Sale and CoreOS. Ask for:
- The exact internal model and hardware platform.
- The correct factory recovery image and matching firmware/driver package.
- Whether CoreOS is a proprietary engineering build or whether the device supports a standard Windows installation.
A normal retail recovery image may not support prototype-specific firmware or hardware.