Microsoft KB Archive/96780

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INFO: Security and Screen Savers

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Q96780

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The information in this article applies to:


 * Microsoft Win32 Application Programming Interface (API), used with:
 * the operating system: Microsoft Windows NT, versions 3.5, 3.51, 4.0
 * the operating system: Microsoft Windows 2000

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SUMMARY
Screen savers are user-mode applications that execute in a different desktop (see the note at the end of the article). Therefore, a screen saver cannot enumerate windows of user-mode applications. This design prevents unauthorized users from viewing the contents of applications displayed on the screen. For secure screen savers (those that ask for a password), this adds a further layer of protection.

Screen savers also execute in the security context of the logged-on user. A screen saver may call ExitWindowsEx, to log off from or shut down the system, or any other application programming interface (API) that the logged-on user has permission to perform.

MORE INFORMATION
A sample screen saver SCRNSAVE is distributed on the Win32 SDK CD.

NOTE: A desktop is a virtual screen. Windows NT 3.5 and earlier have three desktops--the main desktop, the WinLogon desktop, and a desktop for screen savers. Windows NT 3.51 and later support and document creating multiple desktops.

Additional query words: 3.50 Scrnsave Screen Saver Desktop

Keywords : kbAPI kbKernBase kbOSWinNT350 kbOSWinNT351 kbOSWinNT400 kbOSWin2000 kbSecurity kbDSupport kbGrpDSKernBase

Issue type : kbinfo

Technology : kbAudDeveloper kbWin32sSearch kbWin32API