Opening a Spreadsheet in Microsoft Excel

To open an existing spreadsheet, open the Excel application and press Control + O. Find the file through the Open dialogue and press Enter. To find a file in an Open dialogue, press Shift + Tab twice and hunt around the files and folders with the Arrow keys, using Enter to open folders and Backspace to go up a level.
Or a quicker way is to, press Windows + E for File Explorer, find the file (using the hunting method above) and press Enter.
You want a quicker way? Ok, open the Excel application, press Alt + F for the File Menu, Tab to the Recent list and press Enter on the latest file, or Arrow Down to find another recently opened file. Press Enter on the one you want.
Quicker still? Press Windows key for the Start Menu and start typing all or part of the filename. Press Enter if the file is found or Arrow Down to go through search results, pressing Enter on the one you want.