Hi Steve ,
This error can be displayed if the file does not exist in its required default location.
For example on my computer , when I look at the library :
Microsoft Powerpoint 12.0 Object Library
the relevant file is shown by the dialog as :
C:\Program Files (x86)\Microsoft Office\Office12\MSPPT.OLB
The 12 refers to Office 2007 ; if your version is 2010 , it will be 14.0 , and if it is 2013 , it will be 15.0
If the relevant file does not exist in the expected path , then you will have to use the Browse feature to locate it and then specify that as the library to be loaded.
Narayan