(1) Use custome install when you install MS Office, and then you can select which "filter" to install under Microsoft Office Tools, maybe Freelance filter is there. Many many people do not know they missed a lot of things from Office when they install it using Typical installation option.
(2) From Freelance, Save the presentation use "Save As" NOT "save", then you can select which file format to save, look if it has option to save as "RTF: Rich Text Format". Then you can open it from Powerpoint.
(3) If both above do not work, you can install OpenOffice (free) as go between because Openoffice can handle both powerpoint and freelance files download Openoffice from click here