Hi @timothychia
The BIOS cannot detect an Operating system (Windows) on the HDD in the laptop.
This could be due to either a failed HDD or perhaps a corrupted Windows boot partition on the HDD.
Turn on the laptop and quickly press the Esc key a few times and when the startup menu appears press F10.
This will get you to the BIOS menus. When in BIOS scroll though and check if it shows the HDD/SSD model information or not in the ''storage'' menu.
If there's nothing showing there, the HDD/SSD has failed. what is the full model number of the laptop as shown on the product information label on the bottom of the laptop?
If there is model information showing you may be able to repair the Operating system, using a Recovery disc.
You can create a Recovery disc from any known working Win10 (or Win11) PC.All you need is a 16GB USB flashdrive (Win10) or a 32GB flashdrive (Win11) and 1-2 hours of time.
In the host PC go to ''Control Panel > Recovery > Create a recovery drive'' and follow the prompts.
When you have the recovery drive, insert it into the laptop and the turn on the laptop and press Esc key followed by the F9 key.
Change the boot order to boot from the USB drive.
The laptop should boot from the USB drive into the Windows Recovery Environment menus.
When you're in the WRE menus select ''Troubleshooting > Advanced > Startup repair'' and follow the prompts.