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Q102889: Mapping .INI File Entries to the Registry

Article: Q102889
Product(s): Microsoft Windows NT
Version(s): 
Operating System(s): 
Keyword(s): kbenv
Last Modified: 24-DEC-2001

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The information in this article applies to:

- the operating system: Microsoft Windows NT 
- the operating system: Microsoft Windows 2000 
- the operating system: Microsoft Windows XP 
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Under Microsoft Windows NT, Windows 2000, and Windows XP, .INI file variables are mapped into the Registry as defined in the

  \HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\IniFileMapping

mapping key. The Win32 Profile application programming interface (API)
functions look for a mapping by looking up the filename extension portion
of the profile file. If a match is found, then the search continues under
that node for the specified application name. If a match is found, then the
search continues for the variable name. If the variable name is not found,
the value of the (NULL) variable name is a string that points to a node in
the Registry, whose value keys are the variable names. If a specific
mapping is found for the variable name, then its value points to the
Registry value that contains the variable value.

The Profile API calls go to the Windows server to look for an actual .INI
file, and read and write its contents, only if no mapping for either the
application name or filename is found. If there is a mapping for the
filename but not the application name, and there is a (NULL) application
name, the value of the (NULL) variable will be used as the location in the
Registry of the variable, after appending the application name to it.

In the string that points to a Registry node, there are several
prefixes that change the behavior of the .INI file mapping:

  ! - This character forces all writes to go both to the Registry and
      to the .INI file on disk.

  # - This character causes the Registry value to be set to the value
      in the Windows 3.1 .INI file when a new user logs in for the
      first time after setup.

  @ - This character prevents any reads from going to the .INI file
      on disk if the requested data is not found in the Registry.

  USR: - This prefix stands for HKEY_CURRENT_USER, and the text after
         the prefix is relative to that key.

  SYS: - This prefix stands for HKEY_LOCAL_MACHINE\Software, and the
         text after the prefix is relative to that key.

Additional query words: prodnt inifilemapping

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Keywords          : kbenv 
Technology        : kbOSWin2000 kbOSWinSearch kbOSWinXP kbOSWinNTSearch kbOSWinXPSearch
Version           : :

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