JSI Tip 8073. When can the %UserName% environment variable be different than the user name in Active Directory?

In tip 3161 » %UserName% environment variable in a Windows 2000 domain may not be set as expected?, I explained that the %UserName% environment variable can be different than the user name in Active Directory.

When a user logons to Windows 2000, Windows XP, or Windows Server 2003, with an Active Directory user name that contains accents or diacritical marks, the above behavior can occur.

Example:

If a user's name in Active Directory is Jérold, they can type Jerold into the User name box in the Log On to Windows dialog and successfully log on.