Windows Boot Device Missing After BIOS Update on Lenovo IdeaPad S145
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MellowBirch42
I have a Lenovo IdeaPad S145-14. While trying to troubleshoot some other issues, I installed the BIOS update from Lenovo's support site, changing the version from AWCN27WW to AWCN30WW. Since then, the laptop no longer finds a default boot device, and I'm worried it may be bricked. I don't want to lose my files or replace the laptop. Windows repair and system recovery options aren't working, and I'm not very familiar with BIOS settings or creating USB boot media. Could this be caused by the BIOS update resetting settings such as UEFI, Secure Boot, or the boot order? Is there anything safe I can try at home, and would rolling back the BIOS help?
Answers
If the drive is visible in the BIOS but Windows Boot Manager is missing, the disk itself may be fine and only the UEFI boot entry was cleared. Start from a Windows installation USB, choose Repair your computer, open Command Prompt, identify the Windows and EFI partitions with diskpart, and use bcdboot to recreate the boot files. This normally does not erase personal data, but be careful to select the correct Windows partition. If the drive is not detected at all, stop before reinstalling Windows and have the laptop or drive checked.
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Your files are probably still safe. BIOS updates commonly reset firmware settings, including the boot mode and the Windows Boot Manager entry. Enter the BIOS and check that the internal drive is detected, the system is set to UEFI rather than Legacy or CSM, and Secure Boot is configured as it was before. Also check whether Windows Boot Manager appears in the boot list. Avoid changing storage-controller settings randomly, since that can make Windows harder to start.
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I would not roll back the BIOS as the first step. Confirm the drive is detected and restore the correct UEFI settings first. Reflashing or downgrading firmware can create a bigger problem if the wrong file or procedure is used. If the drive is missing from the BIOS, or you’re unsure about partition commands, a repair shop can inspect it without immediately wiping your data.
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MellowBirch42: When I select UEFI mode, there is no EFI or Windows entry listed. I’m going to check the drive and try a Windows installation USB.