If your Excel file has important information and you do not want the file to be edited then you may make the file as a read-only file. Perform the following steps to do so:
1. Open the Microsoft Excel file that you need to make as read-only file.
2. Click File menu and click Save As to open the Save As dialog box.
3. Enter a name in the File name: box.
4. Click Tools button. From the drop-down box, click General Options…
5. From the General Options dialog box, click to place a checkmark beside Read-only recommended.
6. Click OK.
When you try opening the file, you will receive a message box that says that the file should be opened as read-only unless you need to save changes to it. Click Yes. Now, edit data from the file and try saving the Excel workbook. You will receive a warning box that says that the file is a read-only and so on. In order to make changes to the file, you have to save it in a different name. Click OK. You will see the Save As dialog box. Enter a name for the workbook.