Windows Registry: Difference between revisions

Revision as of 04:19, 30 October 2023

The Windows Registry is a unnecessarily nested key-value store.

The following things were noticed after installing the 16-bit version of Internet Explorer 5.01.

This one is bundled with the operating system. Run it with the /v flag to make it actually usable.

It only sees the type registrations (HKEY_CLASSES_ROOT in REGEDT16.EXE).
Spaces in keys are replaced with #.
There is only one value per key ((Default) in REGEDT16.EXE), and it is always a string.
A "Revert to Last Save" menu item exists.
Data is stored in %WINDIR%\REG.DAT.^[1]
Separate REGEDIT.HLP and REGEDITV.HLP files exist. The latter is used for the Help menu when running in verbose mode.

This one comes with the 16-bit version of Internet Explorer 5.01.

The About dialog states this is for both Windows 3.1 and Windows NT 3.51.
HKEY_CURRENT_USER and HKEY_LOCAL_MACHINE are present too.
String, Binary, and DWORD are the only types.
Data is stored in %WINDIR%\REG16X2.DAT.^[2]
REG16X2.Enn for 00-99 are created next to the file for each installation and uninstallation attempt.

The first line is REGEDIT with no version afterwards. Contrast this with REGEDIT4 and Windows Registry Editor Version 5.00 present in later versions.
HKEY_CLASSES_ROOT is explicitly prepended to every key. Contrast this with REGEDIT.EXE /V strongly implying that the root is that itself.
Every processed line has the format HKEY_CLASSES_ROOT\path\to\key = Value of key.
Lines that do not start with HKEY_CLASSES_ROOT are ignored; no special character is needed to start a comment.^[3]
If the = and value are omitted, the key is created without a value.

@@ Line 24: / Line 24: @@
 *String, Binary, and DWORD are the only types.
 *Data is stored in <code>%WINDIR%\REG16X2.DAT</code>.<ref>https://win31.de/etips.htm</ref>
 *<code>REG16X2.E<em>nn</em></code> for 00-99 are created next to the file for each installation and uninstallation attempt.
+=== <code>.REG</code> file format ===
+*The first line is <code>REGEDIT</code> with no version afterwards. Contrast this with <code>REGEDIT4</code> and <code>Windows Registry Editor Version 5.00</code> present in later versions.
+*<code>HKEY_CLASSES_ROOT</code> is explicitly prepended to every key. Contrast this with <code>REGEDIT.EXE /V</code> strongly implying that the root is that itself.
+*Every processed line has the format <code>HKEY_CLASSES_ROOT\path\to\key = Value of key</code>.
+*Lines that do not start with <code>HKEY_CLASSES_ROOT</code> are ignored; no special character is needed to start a comment.<ref><code>%WINDIR%\SYSTEM\SETUP.REG</code> line 4</ref>
+*If the <code> = </code> and value are omitted, the key is created without a value.
 === KB articles ===