Question : One of my Excel file always gives me a "File already open" messge.

I have 1 Excel spreadsheet that always give me this error whenever I open it:

"file.xls is already open. Reopening will cause any changes you made to be discarded. Do you want to reopen file.xls?"

I have tried to rename it and the same thing happens.  This is the only excel spreadsheet it does this one, but it is one I open and close all day long.  Any help would be much appreciated.

Answer : One of my Excel file always gives me a "File already open" messge.

In explorer to to tools > folder options > file types and find the file type in questions. Hit the advanced button select open then try unticking the DDE box. I don't know what the devil this does, but it fixed it for me. We upgraded from 2003 to 2007 when this appeared.