The Windows Desktop Update component implements the RunOnceEx registry key that provides the functionality described in this article. The Windows Desktop Update component is included with Windows 98 and Windows 2000. You can also install the Windows Desktop Update component with Microsoft Internet Explorer 4.0. Note that the syntax and format used for this key is different from the RunOnce key.

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Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

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RunOnceEx Sample to Run Notepad

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx
Title = "My Setup Title"
Flags = dword:00000002

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx\0001
RunMyApp = "||notepad.exe"

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Sample Syntax

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx
Flags = dword:00000000
Title = "Status Dialog Box Title"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx\Depend
0001 = "xxx1"
000X = "xxxx"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx\0001
Entry1 = "MyApp1.exe"
EntryX = "MyApp2.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx\000x
...

Notes

•	"xxx1, xxxx" is a dynamic-link library (DLL) or .ocx file name (such as My.ocx or My.dll).
•	"0001, 000x" are section names. Section names can be alphanumeric.
•	"entry1, entryX" are registry string values that point to a program file to run.

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Definition of Values and Subkeys

Flags is a DWORD value located in the RunOnceEx key to enable/disable the following settings.

Value	Function	Function definition
0x00000000	Default	All functions are disabled
0x00000004	Check Shell Status	Verifies the shell is ready to accept OLE commands
0x00000008	No Error Dialogs	Error dialog boxes are not displayed
0x00000010	Create Error Log File	Create C:\Windows\RunOnceEx.err file if errors occur
0x00000020	Create Execution Log File	Create a C:\Windows\RunOnceEx.log file with status of commands
0x00000040	No Exception Trapping	Does not trap exceptions that occur when registering DLLs
0x00000080	No Status Dialog	Status dialog box is not displayed while RunOnceEx runs

The values are cumulative. If you want "No Status Dialog" and "Create Error Log File," set Flags to hexadecimal 90 (80 + 10).

Title is a STRING value that you can use to fill in the Status dialog box title.

The HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx\Depend registry key contains the .dll files and the .ocx files that should be kept loaded in memory while all sections of RunOnceEx are running.

The HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx\000X registry keys contain entries to be run. These sections are run in alphabetical order. Therefore, the ...\RunOnceEx\0001 section is processed before the ...\RunOnceEx\0002 section.

The string values within a ...RunOnceEx\000x section contain the commands that should be run for the section. The format is: For example: Line1 runs the "my.exe -quiet -url http://www.microsoft.com/" command line. Line2 runs the DllRegisterServer function in Shdocvw.dll.

The HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx\000x\Depend registry key contains the .dll files and the .ocx files that should be kept in memory while section 000x is running.

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