Hard disk sanatize , non-system disk problem

[Rayanee]

• Hey , I'm living in pain , I stayed awake for like 7hours non stop of trying to solve this , I can't,  so I found my mom old PC,  it's an hp Compaq 6400 , when I used it I had a problem , a blue screen keep popping saying that I can't load my PC so I tried slot of time and I accidentally disk sanatize like 5.4% of the hard disk , after that I kept having the black screen saying non-system disk or disk error replace and strike any key when ready , i checked everything , the hard disk is plunged correctly , but i still have the problem , i do not know what to do and i need help , thank you for your attention 

[Paul_Tikkanen]

Hi:

Unfortunately, the only way you are going to fix the problem will be to reinstall the operating system.

I had an old nc6400.  They came with Windows XP, and a few came with Vista.

You can run Windows 7 and Windows 10 on it too, but you will need a product key to reinstall any of the above operating systems and I have no idea where you will be able to find the Windows installation media for such an old notebook anymore unless your mother had upgraded the PC to W10 before you erased part of the disk.