It's not clear exactly what you have done. Elements stores your photos in a database. If you moved the files around on your computer outside of Elements, the program does not know what you have done with them. As far as Elements is concerned, the files are "missing" and show the question mark. While it is possible to relink the photos, this can be a tedious task. If you tell us in a little more detail about where you moved the photos to disc, what you did to clean [your] comp[uter] and how you put photos back on elements 11, we may be able to give you better directions on restoring the photos to your catalog.