Hi:
Here is the link to the diagnostic code site. It isn't going to tell you much of anything.
Hard Disk 1 Quick Test Failure
https://hpcsgen.hpcloud.hp.com/eas-portal/
You need to replace the hard drive and reinstall the operating system.
HP does not make any hard drives, so the hard drive isn't proprietary.
Replace the drive with any capacity that is listed as supported in the parts list at the link below.
Installing drives in excess of 2 TB will require you install W10 in EFI mode, and format the drive in GPT.
http://partsurfer.hp.com/Search.aspx?searchText=G5B65AV
You can reinstall W10 by making bootable installation media using the media creation tool at the link below.
https://www.microsoft.com/en-us/software-download/windows10
Since your PC was upgraded to W10, if you are asked to enter a product key during the installation process, select the 'I don't have a product key' option and W10 will install and automatically activate once you are connected to the internet.
After W10 has completed installing, you can install the drivers and available software from your PC's support page.
https://support.hp.com/us-en/drivers/selfservice/HP-ENVY-Phoenix-810-200-Desktop-PC-series/6879036/m...