Windows 8 & 10
O&O ShutUp10 is a free privacy tool that provides you with full control over which functions in Windows 10 you choose to use and how far data gets shared. The power of privacy is right at your fingertips - choose which unwanted functions you wish to deactivate. Portable Version - no installation required.
Classic Shell/Open Shell
Hate the Modern UI of Windows. Get back control of your START menu.
As of December 2017, Classic Shell was no longer in active development. A new project was started on GitHub using the Classic Shell source code under the name Open Shell.