My 1-year Dell-bundled subscription to McAfee just ended and I won't renew.

I used McAfee's own MCPR.exe to uninstall it and that seemed to work. But there are still 69 items with "McAfee" or "LiveSafe" in their name on my drive. McAfee is even listed as icon that can be displayed in the notification area of taskbar. So Win 10 thinks it's still there, even though the icon doesn't actually appear when I give it permission to appear on the taskbar.

If I try to delete these items there's an error saying I need permission from System. I tried changing permissions for those folders and files since I'm already using an account with Administrator privileges, but that didn't work either

Has anybody successfully removed all this leftover junk?