AFAIK, users of Vista Business should have received (or can get) free downgrades to Windows XP.
XP will certainly run smoother and faster.
By installing XP, you will have to set everything up from scratch again.
In Office 2007, you can click on the Microsoft Office button (icon in top left corner)| program Options button| the Resources tab on the left and hit the activate Microsoft Office button.
See if that applies in 2003 as well.