Alt+Space or Alt+Spacebar is a shortcut key most often used to open the window menu of the program currently open in Microsoft Windows.
How to use the Alt+Space shortcut key
Alt+Space in Microsoft Windows
In Microsoft Windows, the Alt+Space opens the window menu of the program currently open. With this window you can move, size, minimize, maximize, and close the window. For example, while in your computer browser press Alt+Space now and then use the down arrow key to arrow down to Minimize and press Enter your browser window will minimize.
In addition to using the arrow keys in the window menu you can also use its shortcuts, indicated by underline letters. For example, once displayed, R = Restore, M = Move, S = Size, N = Minimize, X = Maximize, and C = Close.
Related keyboard shortcuts
Below are links to related keyboard key and keyboard shortcut pages.