You can compare backups of the core configuration file with your current configuration. This can be useful if, for example:
A previously configured feature is no longer functioning, and you are not sure what in the configuration has changed.
You want to recreate something configured previously, but do not remember what the settings were.
Difference programs can help you to quickly find all changes.
Configuration differences highlighted in WinMerge
There are many such difference-finding programs, such as WinMerge (http://sourceforge.net/projects/winmerge) and the original diff (http://www.gnu.org/s/diffutils). They can compare your configurations, line by line, and highlight parts that are new, modified, or deleted.
For instructions, see your difference program’s documentation.