When software makes decisions for you in a seemingly inconsistent manner, it can be extremely frustrating. For a newcomer to the Office 365 version of Excel, it will probably come as a surprise -- and not a welcome one -- that some workbooks are automatically set to auto-save, and others are not. What drives Excel to choose one mode or the other, and how can one take control over this decision?
Excel users new to Office 365 might also be unhappy about the fact that saving a file no longer brings up the standard file browser that allows you to choose where on your computer you want to save the file. Instead, you get a bewildering dialog box that asks you to "Choose a Location", but favors OneDrive and makes it harder to find locations in your file system outside of OneDrive. "Where's the standard 'Save As' dialog?!? I want to use the same approach to saving a file in Excel as I do in all my other applications!"
How to Get the Experience I Want: Save When I Want, Where I Want
Both of these behaviors are easy to turn off:
Within Excel, click the File menu to open the Excel "Start screen"
Click "Options" -- bottom-left corner
Choose the "Save" page from the left-hand nav list within the Excel Options dialog
Uncheck "AutoSave OneDrive and SharePoint Online files by default in Excel" (which is at the top of the page)
Check "Don't show the Backstage when opening or saving files with keyboard shortcuts"
Check "Save to Computer by default" if you typically save spreadsheets to your local computer
By following the above steps, you'll get an experience that feels familiar, and is probably more in line with what you want.
While you're in there, you might want to change the default folder for the "Save As" dialog. If you save pretty much everything to Dropbox, for example, you can make your Dropbox folder the default for Excel's "Save As" dialog. You'll need to copy-and-paste the path to your Dropbox folder
into the text field labeled "Default local file location".
Why Did Microsoft Do This? Who Would Want Excel To Work This Way?
If you use OneDrive and collaborate with others on Excel files, there's actually a really good reason to enable AutoSave by default for files stored on OneDrive. Doing so allows you to see real-time updates to the file as other people make edits. If this seems like it might be handy, consider turning AutoSave back on and grabbing a partner to experiment with it.
The fact that Excel uses Backstage by default lines up with this: they want to encourage you to save files to OneDrive or SharePoint, where they're automatically backed up and provide better collaboration tools. If you typically work on spreadsheets alone, and store them in your local file system -- or just like to have a consistent and controlled experience -- then you'll probably want to bypass Backstage and use the Windows-standard "Save As" dialog.
How Could This Be Better?
As a software developer, I spend a fair amount of time thinking about how user experience can be improved. My wife recently moved from Windows 7 to Windows 10, and from a 6-year-old laptop to a new one. A lot has changed, and it's hard to lose the familiar and struggle with the learning curve of the new. Sitting with her as she ran into one thing after another in Office 365 that doesn't work the way she wants to, I felt like Software had failed her.
When a new version of an application includes changes that will feel foreign to existing users, and could spike blood pressure and disrupt valuable workflows, it's worth adding some two things: explanatory content, to familiarize the user with what's new; and a brief interview that allows the user to tailor the experience to their own needs. It's not good enough to publish some content on the web and hope that users find it -- the application should incorporate content, making it easy to find -- and easy to dismiss. It can be a hard problem to solve, with users sometimes jumping several major versions, while other users don't want to be bothered with introductory material every time they install an already-familiar application. But the bottom line is that my wife, who loves Excel and uses it constantly, now feels like she's at war with one of her favorite tools. Microsoft, you can do better.