This issue happens when Word is not completely installed or during installation you have chosen certain components to install on first run. If you are consistently facing this issue, I would request you to reinstall word and during installation choose complete install. I am sure this will resolve your issue.
In case, case if you already tried that. Please provide me with the following informatin.
Which version of Word you are using?
Does in ask you to insert Word Cd in the drive during installation.
Do you get any other error message?