I posted this recently and it worked for another user:
The following steps will make PowerPoint 2003 associate .ppt/.pps/.pot file
extensions with itself while keeping .pptx/.pptm/.ppsx/.ppsm/.potx/.potm for
PowerPoint
2007:
1. In Windows, select "Start" | "Run..." menu item to bring up the Run
dialog box.
2. Type in the following command in the "Open" box:
"C:\Program Files\Microsoft Office\OFFICE11\PowerPnt.exe" /regserver
3. Click OK button.
- Chirag
PowerShow - View multiple PowerPoint slide shows simultaneously
http://officeone.mvps.org/powershow/powershow.html
"Gary" <(E-Mail Removed)> wrote in message
news:x7D2l.9681$(E-Mail Removed)...
>I installed PPT 2007 yesterday (using WinXP professional, MS Office 2007
>Home and Student ver) and elected to keep PPT 2003 on my machine until I
>get use to using 2007. Now when I open any power point file it comes up in
>2007. I prefer 2003 for viewing. How do I change my default viewer back
>to 2003? I have researched the entries in this forum all the way back to
>Aug 2008 but do not see anything. TIA......
>