[This is preliminary documentation and subject to change.]
Recommendation (Designed for Microsoft® Windows® Logo)
Instead of opening a registry key with KEY_ALL_ACCESS, use KEY_READ if all your application must do is read the key. Use KEY_WRITE if your application must change the key's value.
By applying this recommendation, your application works better with other processes that may need access to the key. In a complex managed enterprise environment, this can be important.