Duplicate Files Finder is a fast application which checks duplicate files by comparing its file sizes. Because of the method it uses, it is extremely fast but not very accurate. It is available for Windows only.
dupeGuru is more specialized application for finding duplicate files as it compares by contents as well. It is primarily available for Linux and Mac OSX but although no longer developed for Windows, you can download an older version of the program for use on Windows.
HTML5 Character Entity Reference Chart:
During start up or log on, once in a while, you'll see a message just saying Please wait. To turn this message into a more useful message, you can enable verbose messages through a policy setting (local or GP):
Either through gpedit.msc, or, if you're in a domain, through a GPO, navigate to Computer Configuration → Administrative Templates → System. Look for the setting Display highly detailed status messages and set it to Enabled. Reboot to apply the change.