Saving Your Workspace
Creating a workspace is literally as simple as choosing File → Save Workspace, naming the workspace file, and selecting a place in which to save the new workspace file (which is automatically given the filename extension .xlw) in the Save Workspace dialog box. The hard part is actually opening the workbooks you want to work with in the workspace and arranging their windows and display settings the way you want them prior to saving this workspace file. But then, this is the stuff that you have to do anyway to be able to work with more than one Excel workbook at a time.
To re-create the workspace environment, all you have to do is open the workspace file. When looking for the workspace file in the Open dialog box (File → Open), remember that workspace files use the .xlw (for Excel workspace) file extension rather than the normal .xls filename extension.
To have the workspace in your next Excel work session exactly the way you left it at the close of business, don't save the workspace file until after you have saved all your changes to the open Excel workbooks and are ready to exit Excel.
If you've already created the workspace file in a previous work session and want to save any display changes to it under the same filename, choose File → Save Workspace and then click Save in the Save Workspace dialog box. When Excel displays an alert dialog box warning you that you're about to replace the existing file, just click Yes to save your changes to the same workspace file.