Excel will always open in a blank worksheet if you just select it from your
program list.
Get to your files by using File>Open while in Excel. You can also choose "My
Documents" and open specific Excel files from there. Alternatively, you can
create shortcuts on your desktop that will open a particular Excel document.
When you're in File>Open or "My Documents", you can right-click the file you
want to have a shortcut on your desktop and select "Send To> Desktop (create
shortcut)." So now, when you click that icon on your desktop, it will open
Excel and that particular document.
Hope that helps.