You indicate that you wish to isolate an object, and utilize it subsequently without a background.
Try this:
Open the file
Select the object on the background layer
Once the selection is complete, place it on its own layer (CTRL+J)
Delete the background layer. This is critical. You should see the object surrounded by transparency.f
Go to File>save for web. On the dialog, choose PNG-24 for the file type. Be sure that "Transparency" is checked.
Do File>save as.
Open a picture file from your collection. Drag, or copy/paste the PNG file that you have prepared. It should come in without a background.
I am away from my computer at this time. Post back if this works for you.
Sent from my iPad