Open Word then press help then detect and repair, have a tick in restore my shortcuts and you will need the Office CD
Click start then add / remove then click change Office 2003 then click repair.
Before this if you are trying to restore this dll file because of outlook issue. I would request you to Create a new profile in outlook and check. This will help. I have faced one issue where outlook was asking for restoring msncon32.dll. i created new profile and it worked. sometimes this issue is profile specific.