Troubleshooting : Tools : Diff
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-finding programs, such as WinMerge and the original diff can help you to quickly find all changes. They can compare your configurations, line by line, and highlight parts that are new, modified, or deleted.
Figure 93:  Configuration differences highlighted in WinMerge
For instructions, see the documentation for your diff program.