Probably the same thing I did. Downloaded the file from Shiva's site (http://www.hippie.net/shivasite/library/index_files.shtml) and re-started Windows.
Once I did that, AND updated the VBS to 2.3 AND got Microsoft's update to 5.5 (for the runtimes, I think), Visual Pinball now works like a charm!

> So what did you do?
>
> > > Guys,
> > >
> > > I have read and followed each step to installing the required files, however
> > > when I try the VPinMameTest.exe it reports:
> > >
> > > Class Not Registered.
> > > You need the following file installed on your machine. MSSTDFMT.dll
> > >
> > > Hmmm - Where do I get this file from?
> > >
> > > Cheers in advanced.
> > >
> > > [FAR-Q]
> > >
> >
>