Win 9x - Lost clusters explained

A lost cluster (which is also known as a lost file fragment) appears to Windows as in use, but it does not have a file associated with it. Programs such as ScanDisk and Norton Disk Doctor find and fix lost clusters.

What causes lost clusters? Crashes, mostly - by Windows and by applications. If a program crashes while it is creating, copying, or enlarging a file, some of the file's clusters may not be re-marked as available, even though the file with which the clusters are associated no longer uses or needs them. That leaves clusters marked as in use, but with no files or other clusters pointing to them.

A loose or defective drive cable can also cause lost clusters by creating bad sectors within clusters. If your system and applications don't crash often but you still end up with lost clusters, try removing your PC's case and checking the ribbon cables running between the drives and the motherboard. I know of no way a bad drive by itself could cause lost clusters, however.

In theory, you could lose clusters by defragging your drive while running other applications, although today's defraggers make that unlikely. Still, it's safer to defragment your hard drive with no other programs open.

When a disk scanner finds a lost cluster, it gives you two options: save the contents of the cluster as a file so you can look at it and decide if you need it, or mark the cluster as unused to free up wasted disk space.

The safest option is to save the contents as a file, but I have never found anything worth saving in a lost cluster, and I stopped saving them years ago. They virtually always contain extra copies of information that is safely stored elsewhere on the drive.

Join the newsletter!

Or
Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lincoln Spector

PC World
Show Comments

Essentials

James Cook University - Master of Data Science Online Course

Learn more >

Mobile

Sansai 6-Outlet Power Board + 4-Port USB Charging Station

Learn more >

Exec

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?