Update and synchronize user names in SharePoint

Often - people change their names in the organization - getting married, getting divorced, or just decide to change their name because ...

For some reason, SharePoint can not synchronize the new names.

Here's a command  for a version of SharePoint 2007 and up that will help you

stsadm -o migrateuser -oldlogin Domain\OldUserName -newlogin Domain\NewUsername -ignoresidhistory

For a version of SP 2010 and up , With PowerShell

Move-SPUser –Identity "Domain\OldUserName" –NewAlias "Domain\NewUsername"

Enjoy,
Roi