Bunty
It is a faulting add-in .
Try looking under Tools>Add-ins, un-check them all and re-start excel. if
the issue goes away, add one back at a time an re-start Excel between each
iteration until the issue comes back. That's the issue.
If this doesn't work, be suspicious of Adobe Acrobat as this often loads
integration which fails. (You can test this by quickly un-installing the
acrobat and re-start Excel. again if it's gone away, re-load acrobat with
the advanced options and say no to any Office integration)
--
HTH
Nick Hodge
Microsoft MVP - Excel
Southampton, England
(e-mail address removed)
www.nickhodge.co.uk