The latest build of Windows 10 released in January brings a bunch of new features and enhancements. One of these enhancements is the new refined Start menu, which also includes Continuum, a new feature aimed to help hybrid devices to have the best of both worlds (tablet and laptop).
However, the updated Start menu does not allow users to resize the menu, as it was possible before (build 9879). Fortunately, Microsoft did not remove the old menu yet and a simple modification of the Registry can bring it back.
How to bring back resizable Start menu
Open Registry as an administrator and navigate the following path:
Finally create a new DWORD called EnableXamlStartMenu and leave the default value of 0.
Restart your computer and now you can enjoy the old new Start menu.
To revert the settings, simply delete the DWORD key you created on step 2.