When a user attempts to log on remotely to a Terminal Server, the user will appear to start a logon session and get a background displayed, but will then be returned to the Locate Terminal Server dialog box. On the server, an instance of Dr. Watson will be shown in Task Manager, and the Drwtsn32.log file will be generated, as well as a user dump of the memory at the time of the failure. If the same user is logging on to the console of the Terminal Server, rather than remotely, the same thing occurs; however, because Winlogon is a vital system component, the server will display a blue screen STOP 0xC000021a error message.
When a user profile contains a combined environment path that is very long, the Winlogon.exe process that is spawned for the user will have a Dr. Watson error, and the user will be sent back to the Locate Terminal Server dialog box. If the same user logs on to the console of the Terminal Server, it will also cause Winlogon to have a Dr. Watson error, but it will be accompanied by a STOP 0xC000021a blue screen error message.