Those of us who remember DOS also remember that many complex functions performed by software could be quickly accomplished by a striking together a combination of two or three keys, e.g., even today most PC users know that Ctrl-Alt-Del together will reboot the computer.
When most of computer use switched from DOS to Win, these combination keystroke operation commands were replaced with pull-down menus and mouse clicks.  However, use of the old keystroke commands even today enable the speed of much computer work to be substantially increased as compared to using  pull-down menus and mouse clicks.  In other words, if you know some combination keystroke commands, it is possible for you to improve your output at your computer keyboard.  Here is a tabulation of useful keystroke commands for you to try and perhaps use in your computer work.
Control Key Functions
Ctrl-Esc Brings up start menu
Ctrl-Tab Jumps to another area of program
Ctrl-C Copies selected item
Ctrl-N Opens new file in applications
Ctrl-O Triggers File Open dialog box
Ctrl-P Brings up printer dialog box
Ctrl-S Triggers the Save As dialog box
Ctrl-X Cuts selected item
Ctrl-Z Undo last action
Ctrl-Home Go to top of document
Ctrl-End Go to bottom of document
Alt Key Functions
Alt  On desktop, brings up menu bar
Alt-Esc Brings up running  programs one after  the other
Alt-Tab Allows selection of running programs
Alt-Shift-Esc Brings up running programs in the opposite direction
Alt-Shift-Tab Allows selection of running programs in opposite direction
Alt-Spacebar Brings up selection box under icon in left corner
Alt-Enter Resizes DOS windows Full screen/windows
Alt-PrintScreen Copies current window to Clipboard
Alt-F4 Exit programs
Shift Key Functions
Shift-Del Cuts selected text
Shift-Ins Pastes from Clipboard
Shift-End Extends selection to end
Shift-Tab Sends tab in opposite direction
Shift-F10 Brings up selected context menu
Internet Explorer Shortcuts
Ctrl-D Adds current page to "Favorites"
Ctrl-O Goes to new location
Ctrl-P Prints current page or selected text
Ctrl-S Saves current page
F4  Drops down address box
F5  Reloads current page
F11  Toggles full/windowed modes
Esc  Stops downloading current page
Home Goes to top of current page
End  Goes to end of current page
PgDn Scrolls down one screen
PgUp Scrolls  up one screen.