Excel program 2007 does not allow use the majority of commands....
 

Excell program 2007 does not allow to use the commands for any of the
programs like words does not allow to write. On the Excel worksheet does not
allow to write anything in the cells, most commands are in gray( do not allow
to use them). Any file that is link to 2007 like Excel 2003 has the same
problem. And these files are not password protected. What can I do????