With respect, I think you have not spent sufficient time familiarising yourself with the basic functionality of PD9.
Your produced file - mpeg, avi, mov whatever, is saved with the profile/format, to the location, and with the name you specified in the produce window.
The .pds file is purely the editing instructions saved for use at a later date should you wish to store and then continue or re-visit your project. No other programme can use the .pds file.
By close a file, I presume you mean save (or not) and start with a clean workspace/timeline. Try under File>New Project or File>New Workspace.
I would strongly suggest you study the user guide and view the tutorials before making snide remarks about something that is very basic. We are just users trying to help each other voluntarily, not CL technical support or customer service.
Cheers
Adrian
Life is really simple, but we insist on making it complicated. (see below)
Confucius
AMD Phenom IIX6 1055T, win10, 5 internal drives, 7 usb drives, struggling power supply.