Updating excel files
To avoid this, you may want to disconnect certain people from the shared workbook.
The changes by different users are merged into a single workbook.
The recent versions of Excel 2010, 20 make it easy to share and collaborate on workbooks.
By sharing an Excel file, you are giving other users access to the same document and allow them to make edits simultaneously, which saves you the trouble of keeping track of multiple versions.
option only prevents turning off change tracking in a shared workbook, but does not prevent other users from editing or deleting the workbook's contents.
If you want to prevent people from changing important information in your Excel document, you will need to lock some areas before sharing it ("before" is an important word here since the worksheet protection cannot be applied to an Excel shared workbook).