Hi:
That code means the hard drive has to be replaced and the operating system reinstalled.
If you want to first try reinstalling W8.1, you have nothing to lose by trying.
The notebook came with W8.1. If you don't have the installation media, make your own.
Install W8.1 by creating the Microsoft installation media, using another Windows PC...You want W8.1 64 bit.
If you live in an EU country, you probably will have to use the W8.1 N ISO file download.
https://www.microsoft.com/en-us/software-download/windows8ISO
Only if you are asked to enter a product key during the installation process, use this generic key.
This is the generic key for W8.1 'standard.'
334NH-RXG76-64THK-C7CKG-D3VPT
If you had to enter the generic key, manually change the generic product key to the W8.1 'standard' key in your PC's BIOS in the PC settings menu.
After you get W8.1 installed, you will need to run the free utility I zipped up and attached below, that will show you show the W8.1 product key in your PC's BIOS.
I have also zipped up and attached below, the Microsoft tool which hopefully will transfer the ISO file to a DVD or usb flash drive so it is bootable.
Then you can install the available drivers and software from your PC's support page.
https://support.hp.com/us-en/product/HP-15-Notebook-PC-series/7234945/model/7450454/
If you have to replace the hard drive, here is the link to the service manual...
