File: \BCD x000098 error

I have a 5 yrs. old All-in-One HP Pavilion 23. It had Windows 8.1 with Windows 10 upgrade option. About 5 months after Windows 10 release - I upgraded. About ¾ year later it crashed, and I was able to recover to Windows 8.1 and upgrade to Windows 10 again. During this time I had Norton security, and it always seemed a little slow, and then I didn’t renew Norton. Then yesterday I crashed with boot error File: \ BCD. Ran hardware scans and everything is alright. Finally tried going to cmd prompt, and did commands:
Bootrec /fixMBR - this ran alright
Bootrec /fixboot - this said “Access Denied”
Bootrec /scanos - this ran alright
Bootrec /rebuildBCD - this ran alright

After this I had option in Recovery to continue Windows 8.1. So I recover Windows 8.1 and upgraded to Windows 10 again. This morning after turning PC on, it automatically went into what it said was some C: drive corrections, and has been run alright since. I’ve purchased Webroot and installed, and running it. I’m using the PC I’m talking about.
Should I be concerned about the - Bootrec /fixboot - this said “Access Denied” ?
What would be causing this problem?
What can I do?