I only want one sign in option

In a small organizational setting with limited tech support or knowledge about Windows 10 pro. One of our staff has noticed that some of the computers have the option of signing in with a Microsoft account. We only want our users to sign in to our domain with their ID and password that has been given to them. Is there any way to lock the sign in screen so that the only option they have to sign in is the domain using the credentials provided to them? The individual who set up these computers is no longer here so I am uncertain as to what they did to provide this sign in option. We are looking to do this to provide continuity from work station to work station, security, tracking ect. Any help would be greatly appreciated.

Hello and welcome to this Forum :)

I would suggest that the best way is to remove these Microsoft accounts from the computers so that there is no choice offered. You will need to log on as an administrator to do this using one of the domain admin accounts. The tutorial below shows you how to delete user accounts if you are not aware how to do this. Standard Domain users should be prevented from creating new accounts in their set up.

https://www.tenforums.com/tutorials/5464-user-account-delete-windows-10-a.html?filter[1]=User Accounts

Thanks for the tip philc43. I may not have time to check this out today but hopefully tomorrow. Will post my results.