Hello Danny, I seem to remember that the user is advised to first duplicate the image and save the original before editing begins. I do this even though MSD 9 automatically creates a working copy and saves the original at the top of the stack....belts and
braces.
This way you can make your selection, go to the drop down menu and choose crop which has a few more choices, e.g. invert selection, etc. Assuming you are selecting something from the middle of the image the surrounding stuff will be lost ( well actually
it can be retrieved but that's another story). You will then save-as your selection and basically you essentially have a new image that you can do whatever you want with. When you open another image the part-image will go to the stack and you can drag and
drop it onto the new background.
Flatten and save regularly, I got into the habit as my first PC had only 128mb RAM & 8 Gb HDD but it worked well through four PCs upgrades until MS interfered.
I have had to install the Virtual thing which is not a great solution.