In the Windows registry, adding the LegacyDisable string value to a key serves the purpose of instructing Windows to disregard the key, its values and any of its subkeys and subvalues, effectively disabling it.

For example, adding the LegacyDisable string value to the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\opennewwindow

...disables opennewwindow, removing the "Open in New Window" item from Windows Explorer's context menu. CCleaner's context menu cleanup tools also make use of LegacyDisable for this purpose.

However, documentation on the string value seems non-existent; I've not been able to find anything at all documenting it, either on here or via Google, so I'm left confused about where it came from, and whether disabling registry keys is all it was ever intended for, and why it's not documented.

Is disabling registry keys LegacyDisable's only purpose?

When used to disable registry keys, how does its behaviour differ from the other method employed by CCleaner - prepending text data to a string's hex data? Why does CCleaner employ both methods?

Please only answer this question if answering all questions.

In the Windows registry, adding the LegacyDisable string value to a key serves the purpose of instructing Windows to disregard the key, its values and any of its subkeys and subvalues, effectively disabling it.

For example, adding the LegacyDisable string value to the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\opennewwindow

...disables opennewwindow, removing the "Open in New Window" item from Windows Explorer's context menu. CCleaner's context menu cleanup tools also make use of LegacyDisable for this purpose.

However, documentation on the string value seems non-existent; I've not been able to find anything at all documenting it, either on here or via Google, so I'm left confused about where it came from, whether disabling registry keys is all it was ever intended for, and why it's not documented.

Is disabling registry keys LegacyDisable's only purpose?

When used to disable registry keys, how does its behaviour differ from the other method employed by CCleaner - prepending plain text to a string value's hex data? Why does CCleaner employ both methods?