Username difference between site collections

Question

In the root site collection of my SharePoint web application I see the username as first name - last name, but in other site collections the username is displayed as DOMAIN\USERID.

How can I change the settings so that all sites show the username as: first name - last name

Answer 1

I used this Powershell script to do a Active Directory synchronisation:

Get-SPUser –Web http://<URL> | Set-SPUser –SyncFromAD