The disk defragmenter in Windows Vista leaves much to be desired. A couple of months ago, I recommended Auslogics' Disk Defrag as a free alternative. What that program lacks is the ability to defrag just one or a select set of files and folders. If you use Windows XP, the free Contig program from Mark Russinovich of Sysinternals fame (now owned by Microsoft) lets you ensure that an existing file is stored contiguously rather than fragmented onto different disk volumes. You can also use it to create a file that will remain contiguous.
Why would you want to defragment a single file? It may be one you open frequently, or it may be missed by disk defragmenters for any number of reasons, primarily that it is in use when the defrag occurs. A companion program from Russinovich called PageDefrag lets you defragment paging files and Registry hives that are inaccessible to other defraggers.
These programs are great for XP, but they don't work with Vista. For that OS, there's WinContig, a freebie from Marco D'Amato. The program works without having to create any installation files or Registry entries. Simply select the files or folders you want to defrag and click Analyze.
Source:→ C|Net News