Deleting Registry Keys

I installed Comodo Firewall 8.2.0.4674 in Windows 10 Pro (64). The installer stopped at 99% and exited. I tried to remove some leftover keys from registry but the following remain stubbornly, giving an error message when I try to delete them:
HKEY_LOCAL_MACHINE\SOFTWARE\COMODO
HKEY_LOCAL_MACHINE\SYSTEM\Software\COMODO

How can I remove these keys?

What’s the error message?

Have you tried deleting the keys in safe mode?

Thanks Sanya. Deleting key in safe mode was unsuccessful.

The following error message appears:

[attachment deleted by admin]

If you right-click “Comodo” key and click “Permissions” does it show you have permission to it? If you didn’t then the error should say access denied but it’s at least worth looking at.

I did have permissions but changing permissions to full control/read write etc made no difference. I kept receiving an error message on delete.
Anyway, I no longer have the problem as I decided to clean install my os and then update to the latest version of cis.
Thanks for your help Sanya.