Hard drives are cheap and people typically have more space than they know what to do with these days. But, that is no reason to just waste it. When you install Windows patches, hidden folders are created which contain the uninstall data. Viewing the hidden data on my computer, I found 50 or so patch uninstall folders taking up over 500 Mb of space on my drive.
Given enough time and potential to try multiple username and password combinations an attacker might eventually succeed in compromising the security of a server or other computer. Account lockout policies allow you to set thresholds to automatically shut down an account if too many incorrect username and password combinations are attempted in order to protect the machine.
Some experts say that renaming the Administrator account is pointless. Any worthy hacker knows that the true Administrator account has a unique identifier and how to find it. But, that doesn't mean you need to make it easy for the hackers who aren't worthy.
One way for an attacker to scope out a target system and, particularly, to identify the Administrator account so they can focus their efforts on the account with the most privileges is to list, or enumerate, the SID's (serial identifiers) on a Windows machine.
It is difficult to protect devices that you don't even know exist. In larger enterprises it is very easy to lose track of the asset inventory which leads to complacency about rogue devices. In order to effectively protect the network and to respond to incidents efficiently, an updated asset inventory and network map should always be handy.