Article ID: 294739 - View products that this article applies to.
This article was previously published under Q294739
This article describes the different scenarios in which the Fast User Switching feature is available. The availability of the Fast User Switching feature depends upon the following factors:
The Fast User Switching feature is available in Microsoft Windows XP Professional and in Windows XP Home Edition under the conditions that are described in the following sections.
Windows XP Home Edition
Windows XP Professional
Other limitations of the Fast User Switching feature
Computer resourcesThe Fast User Switching feature may not work if there is insufficient computer resources to create a new Winlogon service thread. When there is insufficient resources, the system may stop responding (hang), the system may lock up computer, or the user may receive a Userinit.exe application error and the following error message:
In these cases, some users must log off the computer, or you must close some programs to free up computer resources.
The application failed to initialize properly (0xc000012d)
Third-party graphical identification and authentication productsThe Msgina.dll file interacts with the Winlogon service to provide the Welcome screen and the Fast User Switching feature. Third-party software can replace the current Graphical Identification and Authentication data with their own Graphical Identification and Authentication data. The Fast User Switching feature and the Microsoft Welcome screen are not available if you are using a third-party product that replaces the Microsoft Graphical Identification and Authentication file (Msgina.dll).
For more information about restoring the original Graphical Identification and Authentication file, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/302346/ )The default Windows logon interface may not appear after installing third-party program