Unable to delete the subdirectory

I’m trying to delete directories and subdirectories.
Used Filezilla, WinSCP and also the Online file manager.
And what I treceive is that message: Unable to delete:
Tried to change folder permissions to 777 but this not a unix server…
How I reset the server to the factory default settings?
Or where I can erase my account?

Thenk you.

Just to let you know, all our servers run on Linux, so folder permission masks are actually reflected on the file system. However, especially for older accounts, some system directories may have been created in a way you cannot make changes to them (the folders are owned by root, not by your user).

However, I'm not completely sure whether that's the case here. Can you please tell me which folders you would like to delete and on which account they are found now?