It shows you detailed information about which handles and DLLs processes have opened or loaded. It does what the task manager do with a twist and more information. You can even change the task manager with this one, enable it under its options menu(you must be logged as administrator to do that).
The help file describes Process Explorer operation and usage. If you have problems or questions please visit the Sysinternals Process Explorer Forum.
You can check here the technet page for process explorer.
