Source: KB130539: Third-party disk defragmenter tools for Windows Server 2003, Windows XP, and Windows 2000 I never bothered too much with defragmentations. When I think that my PC is slowing down, I just restore my Acronis BackUp, and have the previous speed again. Thanks for the article @MrNxDmX, it convinced me to try Diskeeper. I do the same and once in awhile a fresh installment follow by a new ATI back up