The best answer to this question can be found at:
PC to Mac and Back
http://www.rdpslides.com/pptfaq/FAQ00281.htm
It depends on what you mean by "will work." Basically it will work. You
should be sure that the 2003 version has been updated to include Service
Pack 1 (without SP1, 2003 often has trouble opening presentations from
other versions). One of the big problems I see is if images were inserted
into PowerPoint by copying and pasting rather than Insert > Picture >
From File. The former method uses Mac-only compression and makes the
pictures not show up on the PC. The latter method should resolve that.
--David
--
David M. Marcovitz
Microsoft PowerPoint MVP
Director of Graduate Programs in Educational Technology
Loyola College in Maryland
Author of _Powerful PowerPoint for Educators_
http://www.loyola.edu/education/PowerfulPowerPoint/