Hi Vladimir Uvarov,
Welcome to the Microsoft Q&A forum. Thank you for sharing the details.
The error message you're seeing usually means your system is working as designed, but Secure Boot cannot verify the current boot signature. This typically happens when the firmware (UEFI) does not have the correct Secure Boot keys or when the boot configuration does not fully match Secure Boot requirements.
Here are some possible checking steps that you can follow to reinstall the default Secure Boot keys:
1, Restart the device and enter BIOS / UEFI setup (press a key like F1, F2, F12, or Esc during boot)
2, Confirm:
- Boot Mode = UEFI
- CSM / Legacy Mode = Disabled
3, Go to Secure Boot settings
- Set Secure Boot Mode = Standard (not Custom)
- Select Install Default Secure Boot Keys / Load Factory Keys
4, Save changes and restart
If the issue persists, please verify that Windows is installed in UEFI mode
- Press Win + R, type
msinfo32 then press Enter
- Check BIOS Mode > must show UEFI
If it shows Legacy, Secure Boot cannot be enabled without converting or reinstalling Windows.
Let me know if you need further assistance, feel free to ask me by clicking "Add Comment" or "Add Answer" if you cannot add comment so your response will be visible. Thanks for your effort.
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