You need to be completely clear about accounts:
1. There is *the* Administrator account, which is disabled and hidden by default. There are a very limited number of scenarios where one would or should enable it. I have never done so on a single machine.
2. There is a user account with Administrator privileges. When one is a single user on a machine this is the kind of account that gets set up when Windows is installed. There always needs to be one account with Admin privileges if you want to be able to install and uninstall software and/or tweak any number of system settings. You must have admin privilege to change the date and time on a Windows machine.
3. There can be multiple additional accounts, created via the user account noted in #2, that may also be granted Administrator privileges or be Standard accounts. If you want the another user to have the sort of abilities to control the system that an Administrator has then you create the account with those privileges. If you want the other user to pretty much be limited to running the software that's already installed and to only be able to customize settings related strictly to their own user environment then you create a Standard account.
[*The* Administrator account is local to the machine in question. The other accounts may be either Microsoft Account linked user accounts or local user accounts.]
Some people choose to keep one account with Administrator privilege and create all other accounts as Standard users, including one for themselves. The account with admin privileges is only logged in to when a task that requires those privileges is being undertaken (e.g., installing or uninstalling software, repartitioning the disk drive, etc.). The standard account is used for day to day computing. This arrangement is the most secure.
For myself, particularly with the advent of User Account Control, I find the above arrangement overkill. I have frequent need to do administrative tasks and do not want to have to switch accounts to do them. For the majority of things like installing software, particularly third party software, you will get a UAC warning telling you that something is trying to install, needs admin privileges to do so, and you answer Yes or No as to whether it can continue. That's way more than enough protection for me.
The following topics by our own quietman7 are, in my opinion, required reading at the outset for those contemplating what's needed to achieve good security:
Best practices for safe computing: