Microsoft Word Error

A couple months ago I got the bright idea to install Microsoft Office 2003 on my desktop, as my dad got the disc with his laptop. However, as it was already registered, we only got 50 uses before having to uninstall it. I let one of my friends borrow our Office 2000 disc, which, of course, he lost. So I downloaded Office 2000 from Limewire and reinstalled it, and it works, but every time I open Word (and close it, for that matter) I get this error: Compile error in hidden module:AutoExec. At the top of the little dialogue box that pops up it says Microsoft Visual Basic. Now, the program still runs fine, but I'd like to know why this is popping up, and if there's anything I can do to get rid of the nuisance.