Odd movement of files

I don?t if it?s a problem but when I ran Defraggler in my sister?s computer early this morning it grouped all the Desktop icons and files to the upper right corner of the screen after Defraggler finished. Usually my sister has them along the perimeter of the screen.

In one of my computer's hard drive contains one folder has multiple folder in it that?s arranged by Date Modified and when I ran it on that hard drive the other day, something happened to two of my folders that modified them as they showed up at the top. I?m not sure if those are the only folders in my drive or my sister?s computer that were modified. Any reason these are happening? Should there be a cause for concern?