Are they .ppt or .pps files?
If yes, then open up the presentation in PowerPoint, click File > Save as.
Under save as type, click on the dropdown. Look for Web page.
Click Save.
Now, look into the output folder for the images.
--
Shawn Toh (tohlz)
Microsoft MVP PowerPoint
Site Updated: June 26, 2007
(All amazing PowerPoint skills here <g>)
http://pptheaven.mvps.org
PowerPoint Heaven - The Power to Animate