Oh, there were a ton of these utils back in the days.

I can't vouch for any of them because I don't use them, but just a quick search for "cpu utilization hdd utilization in the taskbar" shows a lot of options, eg https://entropy6.com/xmeters/

Or even running the default Task Manager so it would be only in the notification area and not in the taskbar: https://superuser.com/questions/666597/always-show-windows-c...