One of the most useful features of Office is AutoRecover. When activated, changes to your work are kept in a hidden file until you save them so should your computer (or your Office application) crash you are offered the option of recovering your last-saved version. Many of us know the hours of work this has saved.
To activate AutoRecover, go to File -> Options in the Office application and click on “Save”. In Excel, it looks like this:
The top option means that if you open an Excel document from OneDrive (or Sharepoint) it will enable AutoSave automatically. This is different from AutoRecover (more on this in the next paragraph). Choose the frequency of your AutoRecover on the basis of how much work you’re willing to redo vs. the performance cost of saving every minute. Finally, the last option will protect against that time you click “Don’t Save” when you meant to click “Save” or “Cancel”.
Now more on AutoSave. This was introduced in Office 365 to work in concert with a OneDrive account. This could be a Personal OneDrive account or a OneDrive for Business account. Keep in mind you can open a free “Personal” account with your work email address and keep your business data separate from your personal data. Personal, in this case, does not mean “not-business”. AutoSave works differently from AutoRecover in that it saves a complete ongoing copy of your document in the specified OneDrive without you having to remember to select “Save”. Sounds perfect, right?
Now for the catch: You are now working in a COPY of your original document and it ONLY saves the ongoing changes to the OneDrive copy of the document. The only way to get your data back to it’s original location is to go to File->Save a Copy and replace the original document. So if you open a document from your Desktop, an external drive or a network share and turn on AutoSave, you are no longer working in that original document. If after hours of entering and changing data you close the document, it will not give you the familiar “Do you want to save changes?”, it will just close. No problem because your data is all saved to the OneDrive. If, forgetting this, you go back to the original document and open it and start entering new data not realizing that the document you’re working with has none of the changes you made previously, you have a problem. Sure, those changes are safely in the document on your OneDrive, but you’ll be left trying to reconcile two completely different documents.
Note: Don’t think the “if I close without saving” option above will help here. Office considers AutoSave a successful save. Remember, you are now working in a completely different document.
My recommendation: only use AutoSave if you are going to work strictly out of your OneDrive folder. This ensures that you are always working with the latest revision. In all cases AutoRecover should be turned on to protect against loss of data due to crashes, but unless you feel confident that you can remember to save a copy to the original location before quitting every time (without prompting) forego AutoSave when working from any source other than your OneDrive.