PRB: Can't Disable CTRL+ESC and ALT+TAB Under Windows NT

Last reviewed: September 29, 1995
Article ID: Q125614

The information in this article applies to:

Microsoft Win32 Application Programming Interface (API) included with:
```
    - Microsoft Windows NT version 3.5
```

SYMPTOMS

CTRL+ESC and ALT+TAB task switching cannot be disabled by an application running under Windows NT.

Capturing WM_SYSCOMMAND messages and not sending them on for processing by DefWindowProc() allowed task switching to be disabled in Windows version 3.1, but it doesn't work under Windows NT.

CAUSE

A primary reason for this change is to avoid dependence on an application for processing of these key combinations. This way a hung application can be switched away from by using either CTRL+ESC or ALT+TAB.

RESOLUTION

CTRL+ESC may disabled on a system-wide basis by replacing the NT Task Manager. This is not recommended.

ALT+TAB and ALT+ESC may be disabled while a particular application is running if that application registers hotkeys for those combinations with Register HotKey().

STATUS

This behavior is by design.

REFERENCES

The first reference below describes the steps that must be taken to replace TASKMAN.EXE. The two additional references provide more information on the Windows NT Task Manager and its relationship to the Program Manager.

ARTICLE-ID:Q89373

TITLE     :Replacing the Windows NT Task Manager

ARTICLE-ID:Q100328

TITLE     :Replacing the Shell (Program Manager)

ARTICLE-ID:Q101659

TITLE     :How Windows NT, 16-Bit Windows 3.1 Task Managers Differ

Additional reference words: 3.50
KBCategory: kbusage kbprb
KBSubcategory: UsrMisc

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Last reviewed: September 29, 1995
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