Double-check the documentation or guides provided by the VDI solution you're using. Sometimes there might be specific steps or considerations that need to be followed during the setup process.

To further diagnose the issue, try creating another user on the VDC and associate them with a virtual machine. See if the same issue occurs for this new user. This can help determine if the problem is specific to the user account you created or if it's a broader configuration issue.

The display of the Windows icon with the "Administrator" login might be a cosmetic issue. When you click on the Windows icon, it might display the default user icon, but the actual login should still be associated with the correct user credentials.

If you're using desktop pools to manage your virtual machines, review the pool configuration settings. Ensure that the pool is being populated with virtual machines based on your template, and that the customization settings are correctly applied to each new virtual machine.

Make sure the role you've assigned to the user grants the necessary permissions for them to log in and access the virtual machine. Check that the role includes permissions related to desktop access and user authentication.

You mentioned that you created a user on the VDC and associated that user with a virtual machine. Double-check that the association has been set up correctly. The user should have the appropriate role and resource assignment to access the virtual machine you've created.

When you create the template, it's important to perform a sysprep or similar process to generalize the image. This step ensures that each virtual machine created from the template starts with a fresh and unique identity, including the ability to set up new user accounts and log in with those credentials. If you didn't perform sysprep or a similar process, it might be causing the issue you're experiencing.

The issue you're describing might be related to how the virtual desktop is being provisioned from the template. When you create a virtual machine template, it might retain some settings from the original template, including the username displayed during the login process. Make sure that you've customized the template to remove any traces of the "Administrator" username and set it up in a way that allows users to log in with their own credentials.

The Windows login name shows the login name of the template machine instead of the user you created.
There could be several reasons why this is happening. One possibility is that there might be an issue with the way the user account was set up on the VDC. You could try checking if the user account was set up correctly and that it is associated with the virtual machine. Another possibility is that there might be an issue with the way the template machine was set up. You could try checking if the template machine was set up correctly and that it is associated with the user account.

The default login account for the VDI is set to Administrator