If these files are defragmented, this may improve performance. Since PageDefrag only affects a small number of files, it takes a relatively short time to run when compared to entire-disk defragmenters like Windows Defrag, so long as the page file is not fragmented. If the page file is fragmented, PageDefrag can take as long as Windows Defrag, or even longer.
PageDefrag does not defragment the contents of the Registry files, only the placement of these files on the hard drive. Numerous other utilities like NTREGOPT examine the contents of the Registry to optimise it.
PageDefrag runs on Windows NT 4.0, Windows 2000, Windows XP, and Windows Server 2003. The tool is not officially supported under Windows Vista or Server 2008 and cannot defragment the pagefile on these platforms, however it is able to defragment Registry hives as with earlier versions of Windows.