I have received a file created in Excel 97 that I cannot open in Excel 2000 either directly by double clicking on its filename in Windows Explorer or from within Excel via File | Open. The file has been sent to me by my eldest son (I am supposed to be the family guru!) with the question why it cannot be opened by several of his colleagues (also Excel 97 users) to whom it was sent for their use.
My simple answer is I do not know why it cannot be opened. I have checked the file for a virus with a negative result. The error message I get is:
filename.xls:file format is not valid
Can anyone suggest a cause for this as I am told it is a recurring problem?