You may be trying to configure and add some keyboard shortcut for some frequently used program, but whenever you try to set it does not gets saved, this problem might happen due to the fact that hotkey has been already assigned to some other program.
ActiveHotKeys is free to use application which allows you to show a list of all active (registered) or inactive (available) global hotkeys. This helps you determine which hotkeys are in use, and which are still available.
This application is portable in nature so no need to install, just run it through its executable. This little application could really come handy when you would like to set certain program shortcuts for your application which you want to launch using a keyboard shortcut or some application which you might have developed yourself.