System diagnostics says No hard drive installed.Please check that the power and data cables are

[M4N1]

Bootdevice not found.

Please install an operating system on your hard disk.

System diagnostics says No hard drive installed.Please check that the power and data cables are connected properly.

Please help.

[CherylG]

Sounds like your SSD has failed and will have to be replaced. Your model uses M.2 SATA SSD such as this:

https://www.amazon.com/Samsung-860-SATA-Internal-MZ-N6E1T0BW/dp/B07864V6CK/ref=sr_1_3?crid=31V0QXLQ3...

Maintenance & Service Guide shows how to change it:
https://support.hp.com/us-en/product/hp-pavilion-14-bk100-laptop-pc/16851367/model/18205286/manuals

If you don't have recovery Media to install windows on a new drive- your Windows 10 license key is embedded in BIOS and you can reinstall Windows without HP Recovery Media. Microsoft provides the free Media Creation Tool to download files and create a Windows 10 usb flash drive.Advantage is you will have latest updated version of Windows 10. At least 8gb flash drive required:
https://www.microsoft.com/en-us/software-download/windows10

Select Download tool now, and select Run.
If you agree to the license terms, select Accept.
On the What do you want to do? page, select Create installation media for another PC, and then select Next.
Select the language, edition, and architecture (64-bit) for Windows 10.
The Guide here shows the steps.Pay attention to Step 5 since you will be using another pc:
https://www.tenforums.com/tutorials/2376-create-bootable-usb-flash-drive-install-windows-10-a.html

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When the flash drive is prepared insert it in a usb port. Power on the laptop and immediately start tapping Esc key. From the menu tap F9 key and use the arrow keys to move to and select usb. Tap Enter key.
When installing it should pickup the key from BIOS but if it asks at any point just choose "I don't have a key". It will continue and should activate once you are online.

This will not include the original software from HP but most of it can be installed from your Support page.