How to determine the "(default)" value of a key

I want to know how can I get the default value of a registry key using C++. I already tried sending NULL or an empty string in the key param in RegQueryValueEx() function.

Tried to check anothe开发者_高级运维r key and I get it right. I just can't get the default. The function returns "" instead of the value.

What do you mean by "key param?" You should be passing NULL or "" as the lpValueName parameter. If that's not working for you then it's a bug in your code. Post your code and perhaps we can provide further assistance.