Hard disk fragmentation will contribute to a significant loss of disk performance and an overall slowing of your PC’s speed. Experts say that the hard drive needs to be defraggmented once in a week or month (depending on the PC usage) for better PC performance.
Windows built-in defragging tool is hardly is able to deliver a good result (but I think Windows 7 is much better). WinUtilities Free Disk Defragmenter can defragment disk more efficiently and reliably.
It is faster than Windows own defragging tool on a fast system. However there is no option for scheduled defragging.
WinUtilities Disk defragmenter (download at source) supports Windows 7, 2000, XP, Vista, 2003 Server, 2000 and 98. 32/64bit versions