A user selects their proper domain and is unable to log into their Windows computer. The error states: `System cannot log you on to the domain because the system's computer account in its primary…

The error message explicitly states "the system's computer account in its primary domain is missing or the password on that account is incorrect," directly indicating an issue with the computer's machine account in Active Directory, such as it being deleted or having a mismatched password.

If the user's account was removed from Active Directory, the error message would typically indicate a problem with the user's logon credentials, not the system's computer account.

If the computer was disjoined from the domain, it would likely report that it could not contact a domain controller or a different error, rather than stating its account is missing or has an incorrect password within the domain.

If the user typed in the wrong password, the error message would typically state that the username or password is incorrect, referring to the user's credentials, not the computer's system account.