Hey there! @mernda96, Welcome to HP forums.
I understand you are getting an error No HD521-2W on your PC.
Don't worry I'd like to help you out.
Did you make any software or hardware changes to your PC?
When and Where do you get this error message?
SMART (Self-Monitoring Analysis and Reporting Technology System) capable hard drives. SMART is firmware that resides on the hard drive and continuously monitors drive parameters such as performance and error rates. SMART uses a technology known as predictive failure analysis to tell you when a hard drive failure is imminent.
The Smart error code would indicate that the Hard Drive is starting to fail and should be replaced.
You can run a system diagnostics test on your PC and check if the hardware components on your PC is working fine.
Refer this article to know more information about hard Drive Failure Errors and diagnostics.
Let me know if this helps!
Have a beautiful day ahead! 🙂
A4Apollo
I am an HP Employee