...
Browse to the folder where the template file exists (O:\Staff\Brand Centre\public\RRU_Templates\Power Point\RRU_Corporate_PPT)
Double click to open the presentation
Click File, Save As
Browse to the folder where templates are saved on your hard drive(C:\Users\<your username>\Documents\Custom Office Templates)
Make sure the type of file to save is "PowerPoint Template"
Give the presentation a name and hit Save.
The presentation template opens and is ready for use.
(Remember that it is a template so if you want to create a presentation now, you should click File, Save As... give the presentation a name and choose the file type of "Powerpoint Presentation".)
In future, when you want to create a presentation, you can click File, Open and then click on the "Personal" option so that you see the templates you've saved, like this:
Double click on the presentation template that you want
Click File, Save As & give it a name, being sure to save the presentation as a regular type of "Powerpoint Presentation"
You're done.