This is not a MS Office issue, it's handled by the operating system.
That said, r-click the "shortcut Icon", select Properties and then
change the "Run" option to Maximized. Please direct any further
questions to the newsgroup for your operating system.
operating system groups have replaced "office" with the particular
operating system name in question, such as "Win2000", "WindowsXP" or
"Win98" as examples.