You select what you want to have double-spaced and right click it. Click "Paragraph" from the menu (after you right clicked). The pop-up menu that comes up lets you deal with the indentions and spacings (after and before) in a more advanced way. Click the drop-down-menu under "line spacing" and click "double." That should give you a preview of the double spacing before you apply the changes (depending on what version you have). That's all, if you have more questions you can funmail me :). Bye
Do you mean the auto-correction in your "Microsoft Office" program removes the extra space when you intentionally type two of them? A "capital space" (one that you type while pressing the shift key) should do the job.
You also can use tabulators in word. Or in excel you can put a semicolon in front of the cell text to prevent any auto correction. Or switch off the auto-correction completely in the options.