Deleted Photoshop files reappear all over my desktop after reboot?

There are about 50 of the stupid Photoshop files that spawn like rabbits on my desktop. I delete them all, even empty the recycle bin, and everything is fine- until I restart the computer. Then they have somehow all returned. I don't know where they come from or why they keep coming back after deleting them. I searched the internet and couldn't seem to find anything about this issue. So now I'm here.