Why is removing the paging file (swap file) and hiberfile needed for a disk defrag?
Paging file (swap file) is a huge file (often about 500 MB) used by Windows to hold some temporary data. Depending on circumstances Windows shrinks or expands this file. Thus the paging files gets spread all over the hard disk in a discontinuous manner. This behavior is one of the main reasons for a poor defrag. Hiberfile is another huge temporary file, which is created if you enable the hibernate feature.