Hello and welcome to the forum.
I suppose in order to recover them, since they are lost, you would first need to find them.
Is that what you mean?
OR
Have the files been deleted or otherwise removed from your computer?
Have you checked the Windows.OLD folder in the root of local disk C:\ ??
I found that when I need to locate something on my PC, if I can remember something in the way of a search parameter that......
"Everything" from here
http://www.voidtools.com/
Usually works wonders.