gconf-editor 里如何把不可写的值改为可编辑？

[yugo]

前两天因为需要把一个健值设为空，然后把它设置成强制值，请问如何改回来？也就是如何unlock 那个值？
不管是normal user 或 root 都该不回来哦~~~

出错内容：
The application "gconf-editor" attempted to change an aspect of your configuration that your system administrator or operating system vendor does not allow you to change. Some of the settings you have selected may not take effect, or may not be restored next time you use the application.