QSettings HKEY_CLASSES_ROOT access

[pdolbey]

Back in the old days of Windows NT, HKEY_CLASSES_ROOT was a simple alias for HKEY_LOCAL_MACHINE\SOFTWARE\Classes. This was a useful thing to know as when trying to read a remote registry with regedt32 (not regedit which never ran remotely), you could exploit this alias.

However in the days of Windows 2000/3 and XP, HKEY_CLASSES_ROOT is actually created from a merger of HKEY_LOCAL_MACHINE\SOFTWARE\Classes and HKEY_CURRENT_USER\SOFTWARE\Classes with values in the latter overriding values in the former. It is this feature that enables features like per-user COM object registration. You need administation right to register objects globally on the machine. You can prove this with regedit by creating the same key in both hives, then seeing which one takes precedence.

Hope this helps

Pete