cannot open excel files
 

Not how problelm started (maybe downloading updates ??) but when i try to
open excel program it asks me for microsoft office cd disk....i cant find my
disk although I do have my license key. When I try to install service pack
3 it also asks me for the microsoft office disk. Is there a way I can
restore this program from my hard drive??? Obviously, I am green when it
comes to computers and knowledge; maybe someone can help? Thanks.