Thank you for responding! These are the steps that I use when creating a new a login in SQL:
1. Right click on "Logins" under "Security" and choose "New Login"
2. In the "Login Name" box, I choose "Search"
3. This brings up a dialog box that where I can choose to search our domain or "Entire Directory". I've added our domain name to the user (mydomain\bsmith) just in case and tried many different users. All ends in the same result.
This is when I receive the error message. I don't get past that. We've been able to create users this way but now receive the error message when trying to do so.
Here are is the code from the script that you suggested-
CREATE LOGIN [ACORP\bsmith] FROM WINDOWS WITH DEFAULT_DATABASE=[AES]
This user was created in our Windows Active Directory a month or so ago.
Thank you again!