Windows’ defragging tool usually works quietly in the background, but sometimes it messes up.
When you suspect the tool is misbehaving, there are easy ways to verify whether it’s working as it should.
What gives with Vista’s defragging?
Joe Payne is suspicious of his Vista system, which has never reported it needs to be defragged.
- “I did a thorough cleaning of my computer’s files (per your [May 2] article) and got rid of about 700MB of clutter. After that, I figured I should defrag the drive. But as usual, Windows said I did not need to. It has never said I need to, and I’ve owned this system for years.
“What gives with defrag? Is it no longer needed, or do you still advise it? I am running Vista.”
Yes, defragging is still a good and needful thing in all versions of Windows. The defragmentation utility built into Windows — defrag.exe — is adequate in XP, moderately good in Vista, and more refined in Win7.
Microsoft Support article 942092 describes what Vista’s (and, to a large extent, Win7’s) defrag engine — Disk Defragmenter — can do and how it’s supposed to work. In short, by default, Vista’s and Win7’s Task Scheduler automatically runs defrag.exe once a week (or on whatever schedule you set) — behind the scenes during system-idle times.
Disk Defragmenter determines whether defragging is needed by estimating the percentage of files that are fragmented. If the fragmentation percentage is low, the tool shuts down for another week. An excellent MSDN article, “Disk defragmentation — background and engineering the Windows 7 improvements,” discusses Windows’ defragging technology from XP through Windows 7. It notes that disk fragmentation falls under the law of diminishing returns: removing even modest amounts of fragmentation won’t significantly improve system performance — especially in Windows 7.