I'm not sure I understand the question, particularly how enabling macros
relates to opening as many pictures as possible. However, if you need to
enable macros, the details depend on the version of PowerPoint you are using.
Try going to the Tools menu and choosing Options. Click on the Security tab
and click the Macro Security button. Choose a setting of Medium for Macro
Security. If these instructions don't work for you, then let us know which
version of PowerPoint you have.
If this doesn't answer your question, try asking again.
--David
David Marcovitz
Microsoft PowerPoint MVP
Author of _Powerful PowerPoint for Educators_
http://www.loyola.edu/education/PowerfulPowerPoint/