Sure can. The easiest way is to open the file (not sure if you saved it as
a .pot or .ppt). Click "File", "Save as", click the "save as type" dropdown
and select the "Design Template" option. This will automatically change
your folder location to the one needed to find this new template. Save it
to that folder. Close it out, open up your presentation you want to change,
click "Format', "Slide Design", and scroll down through your templates until
you find your new design and select it.
Holler back if you have problems.
Bill Foley
Professional Training Technologies, Inc.
www.pttinc.com
Microsoft PowerPoint MVP
Microsoft Office Specialist Master Instructor