One possibility is that the file is read-only. Check the title bar to see whether "read-only" appears after the file name. If so, try to save it under a different name via File, Save As.
Aladin
One possibility is that the file is read-only. Check the title bar to see whether "read-only" appears after the file name. If so, try to save it under a different name via File, Save As.
Aladin
The file is not a read-only. I tried even renaming it and saving it to different locations. It still came back with "File is not saved."
If you can open any other Excel file, edit and save it, then the conclusion should be that something is wrong with your file. As an additional test may I suggest that you send this specific file (if virus-free) to someone who is willing to open, edit and save it.