Sometimes excel workbooks get corrupted.
One cause is opening them from a floppy and saving to that floppy. (Instead you
should use windows explorer to copy to your harddrive/LAN drive), work on it
from there, save it there and use windows explorer to copy it back to the
floppy.)
Another is opening the workbook in MSWord and saving it as an MSWord document
(with a .xls extension).
If someone did the MSWord thing, you maybe able to recover a little bit of your
data by opening it in MSWord and copying and then pasting to excel. (But tons
of stuff will be lost.)
And sometimes the workbooks just get corrupted.
You might be able to recover more by using another program--both xl2002 and
OpenOffice have better reputations for opening files that earlier versions of
excel couldn't.
(
http://www.openoffice.org, a 60-65 meg download or a CD)
If the file is really important, there are commercial recovery services. I've
never used it, but you might want to check into:
http://www.officerecovery.com
Do you have a backup? Any chance you emailed a version to someone who could
email it back?
and one last ditch effort:
Start excel in safe mode and try opening your file.
Windows start button|Run
excel /safe
now file|open to see if your workbook will open.
