One of the limitations of the Windows NT/2000 defragmentation interface is that it is not possible to defragment files that are open for exclusive access. Thus, standard defragmentation programs can neither show you how fragmented your paging files or Registry hives are, nor defragment them. Paging and Registry file fragmentation can be one of the leading causes of performance degradation related to file fragmentation in a system. PageDefrag uses advanced techniques to provide you what commercial defragmenters cannot: the ability for you to see how fragmented your paging files and Registry hives are, and to defragment them. In addition, it defragments event log files and Windows 2000/XP hibernation files (where system memory is saved when you hibernate a laptop).