Help: undefined control sequence: \maketitle

I'm trying hard to adopt LaTEX for my thesis.  Now I'm trying to make a
slideshow for my thesis defense.  I've seen some very impressive PDF
slideshows made with LaTEX, and I'm trying to do likewise.  But every time I
try to use Prosper, I get this output below.

My configuration is Windows XP, and I'm using WinShell.  I think I've got
MikTek in there, but I'm no LaTEX guru, so I may be wrong.  I've scanned the
forums for hours, and I see tips like "update your styles" or such like, but
I don't even know how to do that.  If MikTek or whatever I've got comes
out-dated right out of the box, then how do I get them up to date?

Thanks!

This is pdfeTeX, Version 3.141592-1.20a-rc7.2-2.2 (MiKTeX 2.4)
output format initialized to PDF
entering extended mode
(Defense2.tex
LaTeX2e <2003/12/01>
Babel <v3.8a> and hyphenation patterns for english, french, german, ngerman,
du
mylang, nohyphenation, loaded.
(C:\texmf\tex\latex\prosper\prosper.cls
Document Class: prosper 2001/07/17, v. 1.5
(c) 2000-2001 Frederic Goualard, EPFL, Switzerland
 and Peter Møller Neergaard, Boston Univ., USA
CVSId: $Id: prosper.cls,v 1.24 2002/11/25 14:35:50 exupery Exp $
(C:\texmf\tex\latex\graphics\graphicx.sty
(C:\texmf\tex\latex\graphics\keyval.sty)
(C:\texmf\tex\latex\graphics\graphics.sty
(C:\texmf\tex\latex\graphics\trig.sty
) (C:\texmf\tex\latex\00miktex\graphics.cfg)
(C:\texmf\tex\latex\graphics\pdftex.def)))
(C:\texmf\tex\latex\seminar\seminar.cls
Document Class: seminar 1997/10/13, 1.4
Document Style: `seminar' v1.4 <1997/10/13> (tvz)
(C:\texmf\tex\latex\base\article.cls
Document Class: article 2004/02/16 v1.4f Standard LaTeX document class
(C:\texmf\tex\latex\base\leqno.clo) (C:\texmf\tex\latex\base\size10.clo))
(C:\texmf\tex\latex\seminar\sem-page.sty))
(C:\texmf\tex\latex\seminar\semcolor.sty
Style Option: `semcolor' for doc style `seminar' 1.01 <2004/05/18> (tvz)
(C:\texmf\tex\latex\pstricks\pstricks.sty
(C:\texmf\tex\generic\pstricks\pstricks.tex
`PSTricks' v1.04  <2004/06/22> (tvz)
(C:\texmf\tex\generic\pstricks\pstricks.con))
(C:\texmf\tex\latex\xcolor\xcolor.sty
(C:\texmf\tex\latex\00miktex\color.cfg)))
) (C:\texmf\tex\latex\seminar\semlayer.sty)
(C:\texmf\tex\latex\seminar\seminar.bug)
(C:\texmf\tex\latex\seminar\seminar.bg2
seminar.bg2: various corrections for the Seminar document class added since
sem
inar.bug (waiting Seminar 98)
(Version 1.6 of <November 20, 1997> (D.G.))
) (C:\texmf\tex\latex\hyperref\hyperref.sty
(C:\texmf\tex\latex\hyperref\pd1enc.def)
(C:\texmf\tex\latex\00miktex\hyperref.cfg)
Implicit mode ON; LaTeX internals redefined
(C:\texmf\tex\latex\ltxmisc\url.sty))
*hyperref using driver hdvips*
(C:\texmf\tex\latex\hyperref\hdvips.def
(C:\texmf\tex\latex\hyperref\pdfmark.def))
(C:\texmf\tex\latex\prosper\PPRdefault.sty
`default' style for Prosper ---
CVSId: $Id: PPRdefault.sty,v 1.3 2001/10/24 15:11:25 exupery Exp $

(C:\texmf\tex\latex\amsfonts\amssymb.sty
(C:\texmf\tex\latex\amsfonts\amsfonts.sty))
(C:\texmf\tex\latex\seminar\semhelv.sty
Style Option: `semhelv' for the `seminar' doc style 1.4 <2000/05/08> (tvz)
Modified by Stefan (see source for details)
))) (Defense2.aux) (C:\texmf\tex\context\base\supp-pdf.tex
(C:\texmf\tex\context\base\supp-mis.tex
loading : Context Support Macros / Miscellaneous
)
loading : Context Support Macros / PDF (2004.03.26)
) (C:\texmf\tex\latex\hyperref\nameref.sty) (Defense2.out) (Defense2.out)
(C:\texmf\tex\latex\psnfss\t1phv.fd) (C:\texmf\tex\latex\psnfss\t1ptm.fd)
(C:\texmf\tex\latex\amsfonts\umsa.fd) (C:\texmf\tex\latex\amsfonts\umsb.fd)
! Undefined control sequence.
<recently read> \c@lor@to@ps

l.5 \maketitle

?
! Emergency stop.
<recently read> \c@lor@to@ps

l.5 \maketitle

No pages of output.
Transcript written on Defense2.log.