By default, X‑Plane will install to the Desktop. Though it can be installed elsewhere (by clicking the Change Destination button), it is strongly recommended that it be placed on the Desktop so that the folder can be found in the future, and so it has correct permission settings. Check destination folder with read/write permissions.
You should NOT move the X-Plane executable out of the X-Plane folder.
To move a file use Windows Explorer to navigate to file location you want to copy. Right Click on the Folders (and/or files) and select Copy. Go to the X-Plane folder. Right Click and select Paste. You can also read more here.