Update Windows Registry for all users
Solution 1:
HKEY_CLASSES_ROOT is a pseudo registry hive that contains both the keys found in the per-user settings under HKEY_CURRENT_USER\Software\Classes and the system-global settings under HKEY_LOCAL_MACHINE\Software\Classes. Writes to the HKCR pseudo hive go to the per-user settings under HKCU. If you want to update the system-global settings you should write to HKEY_LOCAL_MACHINE\Software\Classes instead.