Try enabling one of the Excel Add-ins. Solver for instance.

Mark G wrote:

i don't seem to be able to open an excel 2007 spreadsheet from my desktop by
double clicking on it. If i go to the office button and 'open' it's fine.
but double-clicking any excel spreadsheet just opens a blank sheet.

I am using Excel 2007 SP2 and have already unticked the 'ignore other
applications that use DDE'